Engine Surge at WOT
Printed From: CorrectCraftFan.com
Category: General Correct Craft Discussion
Forum Name: General Discussion
Forum Discription: Anything Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=27474
Printed Date: April-29-2024 at 12:54pm
Topic: Engine Surge at WOT
Posted By: levinmark
Subject: Engine Surge at WOT
Date Posted: August-15-2012 at 9:13am
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Good morning, Im having a minor issue at WOT that bothers me a bit on our 96' Ski. Engine is 351w carbed. Boat runs flawlessy throughout power band, except when at WOT after about 30-45 seconds. Engine will loose a little power for a few seconds, like it isnt getting fuel, then it will pick back up to full speed and have no issues. Only time this occurs is when I am footing at WOT, other than that, it runs perfect. Last week I replaced the fuel line, and ASV. Could this be a fuel pump issue at those higher rpms? Appreciat the help guys. Mark ------------- levin |
Replies:
Posted By: Bri892001
Date Posted: August-15-2012 at 2:07pm
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Mark, do you happen to have one of these under the floor panel behind your motorbox? http://www.skidim.com/prodinfo.asp?number=R080024A" rel="nofollow - EFI Inline Fuel Filter Skidim Vince at Skidim said that they are supposed to be a pre-filter for EFI boats, and he hadn't heard of Carb'd boat having one. Mine definitely has one, and I'm curious if they wound up on some later model carbed boats. It would be something to check for, I'd imagine if it got clogged, it could slow the fuel flow. |
Posted By: BuffaloBFN
Date Posted: August-15-2012 at 4:16pm
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Might be as simple as setting the secondary floats as the bowl may be running dry. ------------- http://correctcraftfan.com/diaries/details.asp?ID=2331&sort=&pagenum=12&yrstart=1986&yrend=1990" rel="nofollow - 1988 BFN-sold "It's a Livin' Thing...What a Terrible Thing to Lose" ELO |
Posted By: MI-nick
Date Posted: August-15-2012 at 5:03pm
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sounds like something on the secondary side is a little jacked...float level, needle & seat, booger in the secondary metering block...could be fuel pump too...easy enough to pull the secondary bowl first and see if anything is amiss... ------------- As far as I can tell, I'm not quite sure... |
Posted By: levinmark
Date Posted: August-15-2012 at 9:32pm
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Thanks for the input guys. Brian, I have that exact in-line filter, and that is the only one in the fuel line. I replaced it in the spring and have put a little over 50hrs on it so far, so I am going to replace that first thing and see what happens. If I still have the issue, I will take the carb off and see whats up with the secondary bowl like suggested. Hopefully the new fuel filter solves the problem. I will report back when I get the new one on and tested. Mark ------------- levin |
Posted By: levinmark
Date Posted: August-20-2012 at 3:58pm
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Well fellas, sort of have an update. Havnt put the nnew inline filter yet, hopefully arives today. Anyway, boat ran flawlessly this weekend till I footed. Again, about 30-40 seconds in, starts to die out, then picks up again. After I pulled me wife slalom, I went and out and ran wot with no slowing down. Im thinking there must be some crud in the secondary needle and seat and got through. So, im thinking of just pulling the secondary bowl and cleaning things up and check the float setting. I was reading last night that the secondary float should be set 3/8" off the bowl when inverted. Does this sound right and is there anything else I should scope out while im in there? Thanks for the help! ------------- levin |
Posted By: levinmark
Date Posted: August-20-2012 at 11:56pm
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O.K., one more update. Got the new inline filter installed after work and pulled the secondary bowl. I adjusted the float to parallel when inverted. I must have misread the 3/8" measurement for the float setting. It would of been sitting lower than it was originally set at. So I put it to parallel like I said. Anyway, I sprayed the heck out of the needle and seat area while working it up and down. Reassembled, hooked up the hose and no leaks. I wont be able to get the boat out till Friday to test it. Hopefully the cleaning, readjustment of float, and new fuel filter will cure this issue. I will post the results as soon as we get her out on the water. Thanks for the help. ------------- levin |
Posted By: levinmark
Date Posted: August-25-2012 at 1:49pm
Final update fellas. We went out after work yesturday for some evening runs and it is good to say that the problem is solved with my surge problem. I ran a couple WOT runs and it ran flawlessly  . Thanks for the help with this issue!------------- levin |
Posted By: levinmark
Date Posted: May-05-2013 at 8:58pm
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Good evening everyone, finally had a decent afternoon today and went out for the first ski of the season. As you know from previous posts in this thread, I had surging issues when at WOT, not that I run it that hard much, but I thought I solved the issue, and sure enough at the end of the day, went for a little speed run and it did it again. This what it did. I gave it full throttle and picked up speed just fine, and about 8 seconds into it, surged big time, like almost dying, and then it would pick back up to full speed and surged again like it was dying. It did this a couple times and the last time it did it, it really slowed down and jerked a little and picked back up like a bat out of hell and never slowed down again like it got some debris or something out of the way and had plenty of fuel flow. Before the beginning of the season I took off the secondary float again and readjusted it and cleaned up the needle and seat again, hoping to clean out any debris. I was pretty bummed when it started to surge again. It runs flawless when skiing at 36, just happens at WOT or when footing. I would appreciate any more input and suggestions. If you read previous posts, I replaced the fuel lines, filter, anti syphon vavle, and adjusted floats and cleaned needle and seat previously. Stumped on what to check out next. Thanks for the help. Mark ------------- levin |
Posted By: SNobsessed
Date Posted: May-05-2013 at 9:28pm
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You might want to check the fuel tank vent - an easy way is to leave the cap off for a test. Also - maybe weak fuel pump that can't keep up? Have you watched the secondary butterfly linkage to make sure it isn't intermittently closing? (pinhole in diaphragm maybe). ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: levinmark
Date Posted: May-05-2013 at 10:36pm
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Chris, next time out I will check the fuel vent with the cap off. I have not watched the secondary butterfly to see if it is closing. The carb was new in 2010 and it did not start doing this till last year. We'll see how the weather is this weekend and hopefully get out to check on things. When I first bought the boat I took it to a dealer near us to check things out and the mechanic said that the fuel pump on the boat was not the right one, but would work fine. I didnt think anything of it till now. Maybe there is an issue with that pump and wore out? I'll check the vent and secondary butterfly first and will be in touch. Thanks for the help ------------- levin |
Posted By: TRBenj
Date Posted: May-06-2013 at 12:31pm
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Check the antisiphon valve... Ive seen that exact issue happen a few times and found it to be pretty well clogged up with junk from the tank. ------------- |
Posted By: hotboat
Date Posted: May-06-2013 at 1:15pm
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What ignition system is on this motor? And is there an ei conversion on it? ------------- Brian |
Posted By: levinmark
Date Posted: May-06-2013 at 3:28pm
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I'll check the anti syphon valve, the ignition is just a standard distributor with a prestolite coil ( dont know modeloff hand, ill check aftrt work. Do not know if is orginal to boat or not. There is no efi conversion. New carb was put on it in fall of '10. ------------- levin |
Posted By: hotboat
Date Posted: May-06-2013 at 3:34pm
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Ei = electronic ignition conversion. If it has one clean it and check the spacing, I had one that gave these symptoms ------------- Brian |
Posted By: levinmark
Date Posted: May-06-2013 at 10:12pm
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Brian, I think your right on point with the spacing. I talked with Vince at SkiDim this afternoon and came to the conclusion that I have the electronic ignition with the prestolite distibutor (black and purple wire). He told me to pull the cap and check the spacing between the fins and the rectangular piece and that it is recommended to be set at .010", however they set them up at .006". Afterwork I pulled the cap and sure enough it was way out of adjustment. I should of checked it before moving it but it wasnt even close to .010. So I proceeded to space it at .006" and fired it up. Before the adjustment, I would give the throttle a couple pumps and it would turn over for a 3-5 seconds and fire up. After the adjustment when I turned the key, it fired up instantly. I know that this wasn't my issue to begin with, but what a difference in start-up and idle. Also, how would you go about cleaning up in the distributor cap? Hopefully we'll be able to get out this weekend and give her a run and test it out. Thanks for the input fellas, I'm learning more and more as time goes on. I'll go ahead and clean out the ASV before heading out also, and will take a peak at the secondary butterfly at wot for good measure. Mark ------------- levin |
Posted By: levinmark
Date Posted: May-19-2013 at 11:05pm
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Just an update, we hit the river this afternoon for some runs and I ran the boat WOT a few times and never had any issues! She ran perfect. Thanks for the advice and help everyone. Mark ------------- levin |
Posted By: Hollywood
Date Posted: May-20-2013 at 1:24am
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Great news. Thank you for reporting back so the next victim can search this result. ------------- |
Posted By: MI-nick
Date Posted: May-20-2013 at 2:02pm
do you happen to have a photo of this?? ------------- As far as I can tell, I'm not quite sure... |
levinmark wrote:Posted By: levinmark
Date Posted: May-20-2013 at 3:07pm
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Nick, I did not take any pictures of the distributor. I should have now that I think about it. Basically, when I pulled the cap off the distributor, the center rotor shaft has a splined-like piece about 1" in diameter. These splines are what I am referring to as the fins. To the side of the fins is a little rectangular sensor with a wire attached to it. I simply turned over engine till one of the fins was perpendicular to the sensor and then loosened screw to adjust to .006". Pretty simple fix and made a world of difference. If you need me to, I could pull cap off after work and post a pic. ------------- levin |
Posted By: echobravoecho
Date Posted: May-24-2013 at 12:50pm
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I'll add my experience for the next guy also. 93SN 351W, holley carb, electronic ignition. Same symptoms as the OP, only worse. Slightly different conclusion. Look under the coil packs for resin on the transmission housing. My electronic ignition system was in the process of melting and the cutting in and out at high speed was the first major symptom. The engine started immediately when cold. Ran perfect at ski and wakeboard speeds, until it was time to haul a**. Open the throttle, and the engine sounded like it has a high and low power switch cutting in and out. Top speed was low 40's. At first I blamed it on clogged filter, alcohol in the gas, clogged check valve, etc. etc. Rebuilt the carb, no change, changed power valve and jets, no change, replaced the carb, no change(the rest of the carb circuit was finely tuned, but the initial problem remained.) I had also replaced the plugs and wires earlier. From the forum research, I knew the only thing left was the ignition module, but the failure symptoms didn't match anything I could find that was previously discussed. I purchased a DUI ignition and called my old-school mechanic to help me swap it out since the old ignition pickup has seized in the block and I couldn't pry it out. The first thing he said when we opened the engine cover was, "What's a GM coil pack doing on a Ford engine?" The second thing he said was, "Look at all that resin that has melted out of the circuit board." as he pointed to the bell housing directly under the coil pack. The third thing he said was, "Do you want me to rebuild the coil pack? They are only 30 bucks at the junkyard. Cadillac modules work best." I allowed that since I had already sprung big bucks for the GM based HEI ignition system that I'd pass on the rebuild offer. That was the problem, no more missing, stumbling or cutting in and out. Top speed is now right around 47 MPH on the speedo. Dunno if it's accurate or not, but it runs great now. Regards, Ed |
Posted By: levinmark
Date Posted: May-25-2013 at 8:31am
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Good to hear you got her straightened out. I was getting a little frustrated with the surging, so to finally have the issue resolved is a relief. Sure is nice to have access to the wealth of knowledge available here from everyone. ------------- levin |
Posted By: SNobsessed
Date Posted: May-25-2013 at 10:29am
I searched the 'net for 15 minutes & this is the only picture I could find of the sensor (kit, not assembled). You just loosen the retaining screw & move the pickup until you get the proper gap between sensor & the fin. In the instructions it warns to use a non-magnetic feeler gage.  ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: levinmark
Date Posted: September-08-2013 at 11:38am
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Good morning guys, Unfortunately I am still fighting this darn problem and It seems to be getting worse. The other day the engine started to cut out when I was making a 36mph run through a course which it has never done before. Yesturday I was footing and it was cutting in and out at about 40 and it was way worse than before. Weird thing is that when I hopped back in the boat and took it for a spin (4 people) at WOT, it did not miss a beat the entire length of the lake. Now as soon as there is a load on it (footing, skiing at 36) the darn thing starts acting up. There are no issues what so ever out of the hole, it gets up and goes like crazy. I hear people talking about their coils heating up and causing issues, and was wondering if this might be my problem? After a ski run, I felt the coil and it was definetly hot to touch. I am really getting frustrated with this as you can imagine. Just to recap 96' ski with 351 carb'd, electronic ignition (carb was replaced in fall of '10, new anti-syphon vave, new fuel lines, new filter last fall, new fuel pump) Both primary and secondary floats have been adjusted, needles and seats cleaned out. The one thing I havnt done is pull the dog house and make a footing run with someone looking down the carb to see if fuel is being delivered. The weird thing is that this is occuring when under a heavy load. Once agian, I appreciate the input and advice from all of you, and hopefully we can figure this thing out. Mark ------------- levin |
Posted By: echobravoecho
Date Posted: September-08-2013 at 12:36pm
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Do you have the original electronic ignition, with the separate coil packs? If so, check underneath them for resin dripping out of the bottom of the box and/or onto the transmission housing. That was the symptom on my boat that indicated that they were overheating. The resin looked like amber colored sticky grease by the time it had melted and dripped out. Replaced the electronic ignition with a DUI and my cut-out/hesitation problem was solved. Unfortunately I haven't read of an inexpensive way to test the OEM electronic ignition system, apparently a swap out is the preferred test method. Could get pricey if it didn't fix the problem. I'd guess that an old 351W distributor and coil from the pull-a-part junk yard would be the cheapest way to test the ignition, if you had the time to pull one out. If that fixed the cut-out, you could then decide which type of ignition would suit your needs. Compare the two cam gears and re-use the cam gear at the end of the boat's distributor pickup on the junk yard distributor, it reverses the direction. With the DUI unit, I removed the OEM distributor pickup, and the electronic module with the coil packs on the top, along with the plug wires. The DUI has the coil inside the distributor, so it's self contained. |
Posted By: Bri892001
Date Posted: September-08-2013 at 1:27pm
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Take a footing run in the early evening, preferably a damp evening. With the doghouse removed. (Actually don't know how you'd do this without risking the rope getting caught in the belts, maybe use rear tow point?) Anyway, look for sparks jumping from your wires etc. I'm starting to think ignition on this. |
Posted By: levinmark
Date Posted: September-08-2013 at 1:47pm
Thanks for the replies, I believe the post before Brians was referring to a pro-tec ignition, which I do not have. Here are a few pics. Im getting pretty frustrated. When I foot, I usually go off the fly high pole, so it shouldnt be an issue. Where exactly should I be looking for sparks. My wires and plugs are 3 years old, so they are probly ready for replacement this winter?  ------------- levin |
Posted By: echobravoecho
Date Posted: September-08-2013 at 2:49pm
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Much clearer now with the photo. Suspect the coil/wires/rotor/cap. as this is one symptom for overheated/damaged coils. If you inspect the inside of the cap and don't see a lot of arc damage at the pins and rotor, (sooty black dust and pits/bumps in the metal parts), then change out the coil. If there is evidence of arcing inside the cap and it can't be cleaned up and polished away, change that also. Ed |
Posted By: levinmark
Date Posted: September-08-2013 at 4:43pm
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Thanks for the reply Ed, watching da Bears at the moment, I'll go dig into it at halftime and see what it looks like under the cap. ------------- levin |
Posted By: boardersdad
Date Posted: September-08-2013 at 5:51pm
The problem is obvious--Jay Cutler. ...sorry 
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Posted By: levinmark
Date Posted: September-08-2013 at 6:47pm
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Well I checked out the cap and its looks pretty clean underneath, however the rotor mechanisms look a little rough or used. Should I take some emery cloth and rub under the cap and anywhere else? One thing I did not mention before is when I was adjusting the pickup to the fins on the top of distributor, I had to bump the key to get the fins aligned with the pick up. When doing so, there was some sparking or arcing coming from the coil area. I cant really say where, I just heard a sparking noise. Turned key again, and it looked like it was from the bracket holding the coil in place. I turned the key a few times after and it didnt do it again. If I do go with a new coil, MSD has a couple options and would like to know which one is the correct one for my application. My coil says use with external resistor, I do not know what this is, should I replace cap also while I'm at it? Here are the two I am looking at. Hopefully one of these is the right choice, If not, what should I go with. Thanks again MSD Ignition 8223 - MSD Blaster Coil Details Blaster 3 Coils Coil Specs: Turns ratio: 100:1 Primary resistance: .7 OHMs Secondary resistance: 4.5K OHMs Inductance: 8 mH Maximum voltage: 45,000 Volts (Tested with 6AL Ignition) Peak current: 140 mA Spark duration: 350 uS Features: Extra tall secondary tower for secure coil wire connection Improved output coil for electronic ignitions, and MSD Ignitions (ballast resistor required for points) 100:1 turns ratio and lower primary resistance produce high voltage output MSD Red metal canister is filled with a premium grade oil for cooling Supplied with a 90° spark plug style terminal and boot CARB E.O. Approved or High-Vibration Blaster Coils In applications such as off-road, marine or other harsh conditions, the MSD Blaster High Vibration Coil is the best choice. The sturdy metal housing of the High Vibration Coil is completely potted with a premium grade epoxy to completely encase the coil's primary and secondary windings. This protects the coil's internal components from high and low frequency vibrations that are commonly experienced in racing. Coil Specs: Turns ratio: 100:1 Primary resistance: .7 OHMs Secondary resistance: 4.5K OHMs Inductance: 8 mH Maximum voltage: 45,000 Volts (Tested with 6AL Ignition) Peak current: 140 mA Spark duration: 350 uS Features: Improved output coil for electronic, Point, Blaster or MSD 5, 6, and 7 Series Ignitions (ballast resistor required for points) Alkyd tower with high dielectric properties is less prone to carbon tracking 100:1 turns ratio and lower primary resistance produce high voltage output Metal canister is encased with epoxy to protect the windings from high vibration applications 50 State Legal CARB Legal for OBDII 2003 or Older E.O. D-40-37 Anyway, here a few pics.     ------------- levin |
Posted By: echobravoecho
Date Posted: September-08-2013 at 11:54pm
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That looks like a low time cap and rotor. No visible black soot, the rotor looks slightly discolored on the leading edge, but still it's all good. Unless there is a crack in the cap somewhere that allows the arc to leak out and ground against some near by metal, the cap and rotor don't look like the problem. Which leaves the plug wires and the coil. The only difference between the two coils is that one is filled with oil and the other filled with epoxy, and the blaster three has a funky lengthened secondary tower that might pose an installation problem. Get the epoxy filled. Ballast resister reduces 12V dc to approx 7V dc, the new MSD coils don't need them unless you have points, and you don't have points. Arcing from the coil area is a good indication that some of the internal coil wiring has come in contact with the external case, and this is a good indication that your coil is failing. Since it's dark out you could run the spark/light test this evening as mentioned earlier. Take the engine cover off, mist the engine with the garden hose to promote conductivity, and fire up the engine. Stand back and see if you can visually identify and/or hear any snap, crackle or pop, either from the coil, the distributor, or the plug wires. All of the electrical energy should be contained inside the coil, wires and distributor, any leakage will be visible/audible and also show you where the breakdown in the insulation is occurring. (misting the engine with water encourages the high energy of the spark system to short to ground by providing a lower resistance that dry air.) Safety says not to grab the coil, cap, or wires when the engine is running, although I've heard a few stories to the contrary back in the day. If you just look at the cut out symptoms, the coil is working good enough to let the engine start and run up to a certain heat level and RPM, after which the internal problems introduce enough hysteresis to prevent the magnetic field from rebuilding fast enough to produce enough energy when the breaker opens. Ed |
Posted By: SNobsessed
Date Posted: September-09-2013 at 12:58am
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Levin - I have the same Prestolite EI as you, using the High Vibe coil without resistor. Has worked good for 4+ years. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: levinmark
Date Posted: September-09-2013 at 9:06am
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Thanks for the replies, I'll go with the high vibration coil and I was thinking of ordering the tune-up kit to replace the rotor and cap while I'm in there, also replace the wires and plugs. Anything else I should do, or just pop out the old coil and replace? No other parts needed when replacing the coil? Thanks again and we'll see what happens. Wont be able to hit the water for a week or so, but I'll update when I give her a test run. ------------- levin |
Posted By: Bri892001
Date Posted: September-09-2013 at 10:13am
Could be that the body/case of the coil is breaking down allowing spark to leak to the engine block. I saw that happen with a VW one time. |
Posted By: levinmark
Date Posted: September-18-2013 at 11:16pm
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Thought I'd ask one more question before I take the boat out for a test run this weekend. I purchased and installed the MSD High Vibration coil and plan putting some new plugs and wires on. My question is do I stick with the 8mm plug wires that are on it now, or should I get 8.5-9.5mm wires? Figure I'd replace the wires and plugs since I was at it. Courious as to what you guys would reccomend. Thanks ------------- levin |
Posted By: Bri892001
Date Posted: September-19-2013 at 2:21pm
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I got 8mm for mine. At the time, they were colored yellow (still are on my boat). The same kit on Nautiqueparts is black now. It looks like skidim has an upgraded low resistance 8mm set in blue. 8 is already an upgrade from the 7. Not sure if you'd need to step it up further than that. Maybe for an upgraded ignition or something. |
Posted By: echobravoecho
Date Posted: September-19-2013 at 3:22pm
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I don't think it really matters for the plug wires, a good set of 8's will do the job as well as the 8.5's or 9.5's, and I'd imagine that a set of MSD 8.5 mm wires to match the coil would be great. That coil is rated at 45K Volts, 8mm or 8.5 can handle it no problem. With the additional coil voltage, you might get a better spark with some platinum plugs gapped a little wider to take advantage of the increased energy produced. I say might because after you bump up the performance of the coil, wires and plugs, the weak link becomes the distributor cap and rotor. Your old coil was probably producing about 30K volts, the new one 45K volts. Your existing cap and rotor should handle the increased energy no problem, but again, if, after doing the upgrades, you still get a miss, check the underside of the distributor cap and rotor for signs of arcing. Let us know how it goes this weekend. Ed |
Posted By: levinmark
Date Posted: September-19-2013 at 4:37pm
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Thanks for the replies guys, Do you think my wires are fine, they are PCM wires only three years old and what plugs and gap would you reccomend running? Hopefully wires are ok for now and Ill hit napa for some plugs. Thanks again for the help, Ill let you know how she runs this weekend ------------- levin |
Posted By: echobravoecho
Date Posted: September-19-2013 at 5:50pm
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Nothing wrong with a set of Autolite 24's or their equivalent. The gap is .035. I run NGK plugs on my '94 351, opened the gap to .045. Runs fine with the DUI HEI ignition I put on it, (50KV at the cap) No real reason for the NGK's. Pull the old plugs out before you go to the auto parts store. Compare them to these pictures on this page: http://www.4secondsflat.com/Spark_plug_reading.html or one of the dozens of other sites, and make heat range adjustments accordingly, if required, otherwise, get the same plugs. If they look good enough, don't bother replacing them. Ed |
Posted By: Bri892001
Date Posted: September-19-2013 at 5:50pm
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As long as the wires are good (and have no spots where the insulation has worn through) 3 years isn't that old. These are kind of nice to have, as they help keep the wires off stuff that is hot and/or rotates: http://www.summitracing.com/parts/maa-9-28150/overview/" rel="nofollow - http://www.summitracing.com/parts/maa-9-28150/overview/ You could make use of two sets. |
Posted By: echobravoecho
Date Posted: September-19-2013 at 6:03pm
| Agreed on the plug wires, they look pristine from the photo. |
Posted By: levinmark
Date Posted: September-20-2013 at 12:05am
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Thanks again for he input guys, Ill pull the plugs tomorrow after work and see how they are, I'll keep you informed on how the weekend goes ------------- levin |
Posted By: levinmark
Date Posted: September-22-2013 at 1:02pm
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Alright Brian and Ed, I think my surging issue is finally solved! It must of been the coil. I made few long slalom passes with no issues and then made a handfull of barefoot runs at WOT with no problems, and the footing runs were for a long time, I just held on for the entire length of the lake, sitting down a couple times to give my feet a break. I feel pretty relieved to finally have this fixed, I was getting really frustrated. Thanks again to the both of you for steering me in the right direction with this. Hopefully we'll have a couple more decent weekends of weather here to get back out. Mark ------------- levin |
Posted By: Bri892001
Date Posted: September-23-2013 at 12:14pm
That's good to hear. And, it sounds like most of the other items that were checked/adjusted/replaced along the way were maintenance items anyway. Glad you got it solved 
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Posted By: levinmark
Date Posted: September-01-2014 at 10:02pm
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Well guys I'm back again on this darn thread with issues all of a sudden, again. I thought I had nipped this problem in the butt, but she acted up on me this afternoon. When I was pulling my friend slalom at around 34-35mph, the engine would bog down/cut out every time he would load the line to cross the wake. He is a larger person so he definetly puts a load on the boat when crossing. The bogging down only occurred when he would load the line, otherwise it would catch up and run as he would make his turn, and the would bog down again. I'm lost as to what to look for now. Could this be carb/fuel related? Thanks for the help guys. This is getting very frustrating as you could imagine. Mark ------------- levin |
Posted By: SNobsessed
Date Posted: September-02-2014 at 12:14am
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I would find a valid test procedure before changing any parts. Maybe towing another boat would provide the load to make it act up. Then you can be sure that you definitely fixed it. My guess is weak spark. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: levinmark
Date Posted: September-02-2014 at 8:50am
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Thanks Chris, can you give me a little direction on how to check if I'm getting good spark when the boat is under a load. I'm no mechanic but can usually figure things out and have access to all the goodies to test anything. Appreciate the help. Mark ------------- levin |
Posted By: SNobsessed
Date Posted: September-02-2014 at 10:23am
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This might be worth a try - I bet others will post their recommendation too: http://public.snapon.com/R_RRD/Objects_lg/images/YA840.jpg" rel="nofollow - tester ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: echobravoecho
Date Posted: September-02-2014 at 8:01pm
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I'd say electrical again. Same drill as before, check for physical evidence of the spark energy finding a lower resistance path to ground than thru the spark plugs. Can you get it to bog down for a few moments then shut it down and pull the plugs? The plug that is sooty and black would tell you which plug/wire combo is acting up. On the other hand, buying one of those ignition wire testers would be easier and something you could do in the driveway to check for a cracked plug wire. You could then pull that plug to have a look. Of course the new coil you bought last year could be bad, or the wire connectors need to be dressed and cleaned up, especially the ground wires, both on the engine block ( I think there are two) and on the ground wires themselves, where they are attached to the ground block. How about retarding the timing slightly? That might help clear the problem. After that, I'd get a vacuum gauge and start troubleshooting the engine basics, like shown here: http://www.secondchancegarage.com/public/186.cfm There might be weak springs or crusty valves that is lowering the compression of one cylinder and causing the miss under higher manifold pressure differential. Good luck, hope it's a wire or cable, and not the engine. |
Posted By: Bri892001
Date Posted: September-02-2014 at 9:23pm
| Do you have any play in the distributor? Like if you take the cap off and try and wobble the shaft by holding the rotor, is there much movement there? |
Posted By: levinmark
Date Posted: September-02-2014 at 10:17pm
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Thanks for the info guys. Been a busy day and will try to get to it tomorrow night. I'll clean up all my connections and pull the cap and see if there is any play in the distributor and get a tester. Thanks for getting a plan together to trouble shoot this thing. Ill be in touch when I get to it and let you guys know what I find. Mark ------------- levin |
Posted By: boardersdad
Date Posted: September-03-2014 at 3:33am
| Not sure if anyone mentioned the choke. I was reading the manual on the Holley 4160 on our 84 SN2001, and it says to make sure the electric choke is attached to the basic 12V system and not to the ignition or coil, which would reduce voltage and not open the choke completely and also impair ignition firing efficiency. |
Posted By: levinmark
Date Posted: September-05-2014 at 11:09am
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Just a quick update, pulled cap off and there is no movement of the distributor shaft. I plan on taking some emery clothe and cleaning up all the connections, and getting one of those inline ignition testees and seeing what happens. As far as choke wiring, the wires run into a big bundle of wires, i dont think it is wired to the coil ------------- levin |
Posted By: SNobsessed
Date Posted: September-05-2014 at 11:14am
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Another long shot - is the flame arrestor clean? If it is clogged up, it could restrict airflow. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: Bri892001
Date Posted: September-05-2014 at 11:31am
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Check also to make sure the choke plate slowly opens full when the key is turned on. Or, at least when the engine is running (the engine may need to be running to open it all the way). If it's not opening fully, that could restrict airflow as well. |
Posted By: GottaSki
Date Posted: September-05-2014 at 11:35am
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I believe you still have a fuel flow issue, not electrical. Recommend diassembling the tank's dip tube and fittings. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: SNobsessed
Date Posted: September-05-2014 at 2:47pm
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Pretty soon we will have your boat in 500 separate pcs! ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: levinmark
Date Posted: September-05-2014 at 4:12pm
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Hey, whatever it takes to fix this dang issue! Ill check the choke plate and see what happens when I turn the key. Plan on headn to the quarry tomorrow after work, Ill be in touch with my findings. Thanks again for the guidance fellas! ------------- levin |
Posted By: backfoot100
Date Posted: September-05-2014 at 4:41pm
This is definitely a problem. If you have no movement, you're not getting any ignition advance. That has to be freed up before you do anything else. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: Bri892001
Date Posted: September-05-2014 at 4:45pm
He might have just been checking for wobble, rather than twist. |
Posted By: gun-driver
Date Posted: September-05-2014 at 4:53pm
I agree with above WOT stumble with no lower RPM problems is more than likely not enough fuel flow. |
Posted By: levinmark
Date Posted: September-08-2014 at 2:18pm
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Well I didnt get achance to get out this weekend but I did touch up a few things. i cleaned all my connections and grounds, cleaned air filter which was gummed up with alot of crud, stRted boat and watched choke plate fully open.I took the volt meter and checked at choke, coil, alt. etc. and everything was reading 12 volts. I have never messed with the carb setting screws, can you guys give me some insight if I should and how, also was going to check timing . Thanks Mark ------------- levin |
Posted By: peter1234
Date Posted: September-08-2014 at 3:35pm
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the set screws on the carb are only there for idle wot would or should not be affected by them ------------- former skylark owner now a formula but I cant let this place go |
Posted By: peter1234
Date Posted: September-08-2014 at 3:39pm
I second that for sure the only thing electrically that would cause that is if the spark is hopping around in the cap but you should see that issue at all ranges of throttle probably. does it sound like little gunshots in the engine area while running wot for a bit? if so then it sounds like detonation sometimes caused by a lean condition ------------- former skylark owner now a formula but I cant let this place go |
Posted By: levinmark
Date Posted: September-10-2014 at 5:56pm
Just an update fellas. Today I got a timing light from a friend and checked it out. She was definitely outta whack to say the least. I was reading between 14*-16* @ 600 rpm. So I retarded it back to 10* @ 600 rpm. Maybe this will help out some with the issue I have been dealing with, or at least I can check one more thing of the list  ------------- levin |
Posted By: 63 Skier
Date Posted: September-10-2014 at 7:08pm
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I think Eddie mentioned above that maybe your advance isn't working right. Not sure what type of timing light you borrowed, but would be nice to be able to check total timing as well to make sure you are advancing to where you want to be. ------------- '63 American Skier - '98 Sport Nautique |
Posted By: levinmark
Date Posted: September-10-2014 at 7:42pm
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The light is an old snap on timer but he has another one I ask to use. I need one that will read total advance? And what would the procedure to check total advance? Thanks for the help ------------- levin |
Posted By: SNobsessed
Date Posted: September-10-2014 at 8:43pm
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Old school timing light is fine - just measure the arc length from 0-10 degrees & project it out to 30 degrees. You should get close to 30 deg. by 4000 RPM. If that is happening, then ignition advance isn't causing the miss. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: 63 Skier
Date Posted: September-10-2014 at 9:10pm
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Chris, is 30 total what we want on these engines? I thought it was a bit more, 32-34 degrees, but maybe I'm wrong. ------------- '63 American Skier - '98 Sport Nautique |
Posted By: boardersdad
Date Posted: September-10-2014 at 9:29pm
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Read http://www.correctcraftfan.com/forum/forum_posts.asp?TID=12814&PN=1#144007" rel="nofollow - this old post . I also like http://www.fordmuscle.com/archives/2000/03/timing/index.shtml" rel="nofollow - this article which discusses the basics (non-marine specific). |
Posted By: levinmark
Date Posted: September-10-2014 at 10:22pm
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Thanks for the info guys, Chris, could you elaborate a bit more on what you mean by measuring the arc length from 0-10 degrees and projecting it out to 30. Are you saying measure out to 30 degrees on the balancer and make a mark, shoot it with the light at around 4000 rpm and the mark and indicator should be close to being lined up? ------------- levin |
Posted By: SNobsessed
Date Posted: September-11-2014 at 12:17am
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David - I may be incorrect on the 30 degrees for Levin's '96 (not sure what ignition system he has). My comment was base on my old OEM prestolite which had only 18 deg of advance & it took 4000 RPM to get there. Levin - What they suggested you do is to verify that the timing changes (advances) with increase in RPM. Not sure what your specs are but any system would have at least 18-20 degrees of advance (beyond initial setting) by 4000 RPM. David is right about modern systems having up to 24 degrees coming in by 3000 RPM (in fact my current dizzy does this). If you measure a curved line (arc length) from zero to the 10 deg mark (let's pretend it is 1 inch) then you can measure 1 inch from 10 degree mark & that would be 20 degrees. One more inch & you have 30. You could use chord length (straight line) instead (this would work well with calipers), with same result. A dot of white paint will make the new 30 degree mark easy to see with the strobe light. If you are getting advance, pointer should be near the new mark at high RPM. Have someone run the throttle up by 500 RPM increments, then you can even write down the results & draw a curve. This isn't very precise, but you are just looking to see that it is in the ballpark. I hope this helps. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: levinmark
Date Posted: September-11-2014 at 8:38am
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Thanks Chris, I understand what your saying now. I'll try to get to it tonight after work and see what happens. Fyi, I have a prestolite distributor with electronic inginition. ------------- levin |
Posted By: echobravoecho
Date Posted: September-11-2014 at 7:32pm
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Prestolite distributor with electronic points, right? Back to the timing light. You removed about 6 degrees of initial timing advance, yes? That should have an impact on your total advance and any high end miss. But as mentioned above, you should check you distributor for mechanical advance correct operation in case it is stuck and the previous solution was to advance the initial timing to compensate for the problem. Pull the cap from the distributor, see if you can look down the dist. behind the armature plate (the plate that holds your electronic points). You are looking for the limit plate and/or the springs. If you can't see it, pull the electronic points and the armature plate out, then take a screwdriver and exercise the limit plate, turning the plate and letting the springs snap shut. There are weights attached to the springs that act on the limit plate, you should be able to move them against the spring force and check for lack of a better word, linear movement. If you can't move the plate with your screwdriver, or there is some dragging and scratching going on, then your timing advance is stuck and needs to be serviced. That would cause a no timing advance condition. Reassemble the dist., start the engine and recheck the initial timing at idle. Adjust again if it moved. Rev the motor and you should see the timing mark start to move away from the pointer. It should move about an inch or more away from the pointer. That tells you that the mechanical advance (the springs and weights inside the dist. ) is working. I believe that the total advance should be all in by 2500 rpm, you could also check and record the max advance since you are working on a high rpm problem. If your engine bogs at high load at 3000 rpm, then the total advance could be too high, and should have been addressed yesterday when you retarded the timing from 16 to 10 degrees. Did you mention what the RPM was when the fat man pulled the rope? If the RPM was over 2500, then the mechanical advance was all in by then, and then the problem would point to the carb. If the RPM was below 2500, then the distributor still might have a problem. This is kind of an aside, but I once replace the breaker points on a 57 MGA with the electronic points in an effort to repair a intermittent loss of spark problem. I was hoping that the laws of physics would be suspended in my case because I couldn't figure out why the engine would run fine for an hour, then suddenly quit. Turns out the distributor shaft was broken in such a way that the thing would spin fine for a hour or two, then suddenly skip and stop running. My MG mechanic found it, not I. The point being that the I tried to repair the thing using the electronic points, when the breaker points were just fine. Speaking of that, it might do you good to pull your distributor out of the engine and inspect all the little bits. If that is all good, then I'd focus my attention on the carb. Speaking of carbs, I've got the same engine with the red-hot marine DUI ignition in place of the factory electronic ignition, properly timed, the spark is hotter than hades, and I still have an off idle bog when hammering the throttle. My carb still needs a lot of tuning, and it's new. |
Posted By: levinmark
Date Posted: September-13-2014 at 8:49am
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Thanks for the insight Ed. I'm planning on digging in on it today after work or tomorrow, so we'll see what we find. If by chance the plate and springs in the distributor are not moving freely as they should be, is there any way to lubricate them or is that a no no? ------------- levin |
Posted By: levinmark
Date Posted: September-14-2014 at 1:58pm
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Ok guys, I was able to get a chance to get to the boat this morning. I took the cap, rotor, and plate off and took screw driver and was able to move the advance weights without any limitations. Here is a pic of the balancer with the timing marks. http://s1224.photobucket.com/user/midwestlevin/media/Mobile%20Uploads/photo_zpsad39adb1.jpg.html" rel="nofollow">  [/IMG]You can see that it is marked over to 30 degrees as indicated with the marker. I ran it for awhile to let warm up and rechecked initial timing to 10 degrees and proceeded to rev engine taking timing readings Here are my findings: 10 degrees @ 600 rpm idle 17 degrees @ 2000 rpm 19 degrees @ 3000 rpm 22 degrees @ 4000 rpm Are these normal readings that I am looking at and are there any other suggestions. Probly wont be able to get it on the water soon, but am anxious to see how she goes. Thanks again for the help ------------- levin |
Posted By: SNobsessed
Date Posted: September-14-2014 at 10:32pm
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I would say that your timing is not advancing enough. I don't know if this is causing the running problem but it should be fixed anyway. I had bought a the same dizzy that you have from ebay, & then I sent it to a dizzy repair shop to have the advance curve dialed in. He lengthened the grooves for the weight guides & put in lighter springs. It was $30 well spent. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: levinmark
Date Posted: September-15-2014 at 9:50pm
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Just additional information from today. I warmed up engine and ran it up to 4000 rpm a couple times and did a compression test and here are my results along with pictures of the plugs. 1-150 2-145 3-145 4-152 5-150 6-148 7-148 8-159 This is plug #5, not as sooty/black as the others http://s1224.photobucket.com/user/midwestlevin/media/Mobile%20Uploads/photo_zps51d51694.jpg.html" rel="nofollow">  [/IMG]This what all the others looked like. Any thoughts on compression readings and the plugs? http://s1224.photobucket.com/user/midwestlevin/media/Mobile%20Uploads/photo_zps74f62c97.jpg.html" rel="nofollow">  [/IMG]------------- levin |
Posted By: SNobsessed
Date Posted: September-16-2014 at 9:49am
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Levin - I was having similar plug fouling. The cause was bad valve guide seals. I was able to change them without removing heads. To keep valve from falling in, I fed rope into the cyl. Your compression #s look very healthy! ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: GottaSki
Date Posted: September-16-2014 at 10:36am
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I concur with Chris, Something is amiss with the advance. With initial at 10-12, the final should be about 36 degrees and all in before 3500. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: JPASS
Date Posted: September-16-2014 at 11:05am
Would a leak down test show this? ------------- '92 Correctcraft Ski Nautique |
Posted By: Donald80SN
Date Posted: September-16-2014 at 12:08pm
| I have found that Valve Guides can be a common issue with the Chevy Engines. I have a 1987 305 that has had leaky valve guides for years. At each start-up it puffs some smoke and then it goes away. This particular car gets very little use each year. |
Posted By: echobravoecho
Date Posted: September-16-2014 at 2:05pm
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Minimum compression around 100, new around 170. Yours are great. On the plugs, you have to determine if the black build up is carbon or oil. It's hard to tell from the photo. http://www.aa1car.com/library/reading_spark_plugs.jpg It looks like carbon from here, which would be weak ignition or over-rich mixture. Or just a lot of idling around, with either or both weak ignition or rich mixture. Fix the ignition first, there is no use to adjust the carb until the spark is hot and correctly timed. You already know that your mechanical advance is not advancing, I suggest that you fix that next. You've already cleaned the grounds and installed a new coil. I don't know if anyone else does this, but whenever I find a fouled a plug I clean it and then check for a visible, fat blue spark before re-installing them. Even new plugs. This is from years of messing with motorcycles with weak ignitions. Plug the plug back into the cap, lay it against the side of block and hit the starter. Big blue spark tells you that the plug and plug wire are good, yellow weak spark means replace plug and/or wire. Yellow weak spark on all 8 means bad coil or primary coil wire or rotor and/or cap. Usual safety disclaimers apply. After that, time to move on to the carb. |
Posted By: 63 Skier
Date Posted: September-16-2014 at 5:37pm
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Have you been burning any oil? ------------- '63 American Skier - '98 Sport Nautique |
Posted By: peter1234
Date Posted: September-16-2014 at 8:06pm
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i feel like i am eating a slice of humble pie with the 15 or 20 times in my life i replaced chev valve seals ...ford mushroom seals work the best god did i just say that? and i would say no on the seals showing up on a leak down test. they re only there for drip control when the valve is open if i am not mistaken ------------- former skylark owner now a formula but I cant let this place go |
Posted By: peter1234
Date Posted: September-16-2014 at 8:15pm
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i think at the end of the day you will after all the timing,distributer fixes you are going to find a carb or fuel lean condition ------------- former skylark owner now a formula but I cant let this place go |
Posted By: levinmark
Date Posted: September-16-2014 at 8:17pm
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To answer a couple questions, the plugs are sooty and not oily, I guess that means running pretty rich. I replaced the plugs last fall during winter layup and have only put about 30 hours on it this year, and no, I do not burn any oil. I check it before every outing and after and looks like just changed it. Is replacing the valve seals a fairly simple process. I know I can handle it with a little guidance if I do have to. Plan is to get out this weekend to see how she goes, I plan on changing plugs and testing each on to test spark. Thanks guys for all the input with this. ------------- levin |
Posted By: Bri892001
Date Posted: September-16-2014 at 8:56pm
| I wouldn't think valve seals would cause a surge though, even if you did need them and it sounds like you don't. |
Posted By: SNobsessed
Date Posted: September-16-2014 at 9:11pm
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If the plugs were not oily, I agree bad vavle seals probably not in play. BTW my ('89) 351W has the newer style stem seals. They were hardened & cracked when I replaced them (was at about 1000 hr mark). It was not a 1 day job for me, more like 1 cyl per day! ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: levinmark
Date Posted: September-16-2014 at 10:33pm
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Well we will get to the bottom of this one way or the other. Right now shes sitting at 1300 hrs. Ill just keep plugging away at it and eventually get it figured out. I really appreciate everyones input, what a great resource this site is. Were pretty lucky ------------- levin |
Posted By: 63 Skier
Date Posted: September-17-2014 at 12:38am
Mark, like a few have said I think you have multiple problems. If you aren't burning any oil the valve seals are probably OK, or at least OK enough to ignore for now. So you likely have a combination of ignition and fuel delivery issues. Since timing is straightforward and can be easily measured, tackle that first. You need to get your total timing into range, 22 degrees just isn't in the ballpark of what you should have. The advance mechanism isn't working correctly. Once you get the timing solved, you can run it and see where you are, read the plugs again after cleaning them or installing new. It's possible that will do it, that your lack of advance isn't allowing a complete fuel burn since it doesn't ignite early enough in the stroke. If not you can then turn to the carb, but at least at that point you'll know your ignition is working properly. ------------- '63 American Skier - '98 Sport Nautique |
Posted By: levinmark
Date Posted: September-17-2014 at 1:06am
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10-4 Dave. I know this doesnt fix the timing issue but what if I were to set the timing at the 3500-4000 range to 28-30 degrres and let the initial be where it ends up? Install new plugs, run it this weekend and check them out? ------------- levin |
Posted By: 63 Skier
Date Posted: September-17-2014 at 1:33am
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You won't be able to run it with 16-20 degrees initial, that's way too advanced for idle. Echobravoecho in a post above recommended really getting into the advance mechanism. It's not hard to get at, and simple enough to see if it's working smoothly. Maybe someone prior to you messed with it, changed out the springs? ------------- '63 American Skier - '98 Sport Nautique |
Posted By: hotboat
Date Posted: September-17-2014 at 7:13am
Don't worry on the initial, on this low of a compression motor it should be no problem and will idle much better. Get that timing at 4000 up in the 30-36 range ------------- Brian |
Posted By: levinmark
Date Posted: September-17-2014 at 8:53am
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Thanks guys, Ill mess around with it and see how it goes Saturday. Ill keep you guys posted ------------- levin |
Posted By: levinmark
Date Posted: September-17-2014 at 3:20pm
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One more question. Im doing all this work in my garage with motor having no load. Im assuming if I advance the timing more, it needs to be checked under load, like running down the lake wot or at least 3500 rpms and check timing then to see if its still in ballpark? ------------- levin |
Posted By: Bri892001
Date Posted: September-17-2014 at 3:34pm
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The advance in this application works strictly on RPMS. So, load doesn't matter as far as the dizzy is concerned. I'll let other's weigh in on whether or not you want to rev it over 3.5k rpms in neutral though. I wouldn't go over 3, but that's just opinion. |
Posted By: Bri892001
Date Posted: September-17-2014 at 3:49pm
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Here's a weird one I'll throw in there. Luchog ran across a situation where the spring that holds the cap contact to the top of the rotor was sticking somehow. Worth exploring: http://www.correctcraftfan.com/forum/forum_posts.asp?TID=19567&title=distributor-cap-carbon-pill-issue" rel="nofollow - http://www.correctcraftfan.com/forum/forum_posts.asp?TID=19567&title=distributor-cap-carbon-pill-issue |
Posted By: phatsat67
Date Posted: September-17-2014 at 4:02pm
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Lack of full timing advance won't cause a surge. It will just make it doggy all around. Inaccurate advance IE. jumping around would cause a surge as it made more and less power but that's unlikely. Just rev it through the rpm range until it doesn't advance anymore. 3500 rpms in neutral won't hurt a thing. Make sure the timing reading you see advances in a linear motion and it's not "sticky" or "jumpy". ------------- |