'88 SN speed problem? |
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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Posted: April-18-2010 at 2:51am |
Hi all,
This is my first inboard, and I know they are not built for speed. I'm concerned about my boat, though. We had it out for the first time today and it would only top out at 36-37 mph. I was expecting at least 40-42. Can anyone chime in with what speeds this boat should be running? 36 doesn't seem right, and it took it a little while to get there. I kept getting a random pop now and then from the exhaust like maybe there was a miss. Once it warmed up, it also became a little stubborn about starting. I'm not quite sure where to start. Should I change the plugs and do a little tune-up? Or is it more likely a fuel problem? The previous owner has added a Holley Pro-jection system and I believe some sort of electronic ignition conversion if that makes any sense. I'm new to these machines...any advice is greatly appreciated. Thanks!! |
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Travis,
Sounds like you have a problem due to the PO's thinking his "upgrades" were a sound idea. Is the Holley even "marine" rated? I wish I could help. The best I can do is recommend you find someone that may know something about that Holley system. Remembering back to previous threads, I believe 3 have tried the Holley and I know two pulled them off and went back to a carb. What WOT RPM's are you turning up? What prop is on the boat? Can you get in touch with the PO and get the OEM parts back? |
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BuffaloBFN
Grand Poobah Joined: June-24-2007 Location: Gainesville,GA Status: Offline Points: 6094 |
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Along with what Pete said, it also sounds like the timing could be off. I'm basing that on carb symptoms though...not injection.
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eric lavine
Grand Poobah Joined: August-13-2006 Location: United States Status: Offline Points: 13413 |
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chessloves is from Lawrence, you know him? the most important info you can come up with at this point is your Wide open throttle (all she has) and post, look at the prop and post those numbers also...alot of guys will spin them up to 5400 and get 35 mph, under propped or the opposite. you may have to much prop and no power to turn it....thats why its important to list your WOT, im sure most will agree. first things first, determine if it is a prop issue or a power issue
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"the things you own will start to own you"
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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Hi guys,
It's always a learning process with a used boat like this. I'm gradually learning what has been done to the boat. The PO seemed pretty meticulous, and kept all the OEM parts. I have them in a box. There is a control module for the fuel injection and I have the manual for it...maybe it just needs some adjustment or something. As far as numbers, I was only getting about 3700 RPM out of it yesterday...about 1:1 with the MPH as I think it probably should be. I'm still wondering if I might have a plug fouled with fogging oil or something simple. The boat seemed to run fine when I bought it just before winter. The prop on the boat is a OJ Stainless 4-blade...it reads OJ 102 on the side and has a 13 stamped on the hub. The spare prop is a OJ 4-blade 13x13...same? I don't know chesslove...but may try to look him up. Thanks!! |
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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jimbo
Senior Member Joined: September-07-2004 Location: United States Status: Offline Points: 473 |
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I'd start with a Spring tune up (new plugs, wires if they look old, new cap and rotor, new fuel filter). Run the tank down then fill it up with fresh fuel and a can of Sea Foam. (Actually, run the tank down, then replace the fuel filter).
When you pull the plugs, look for anything unusual. I'd also recommend a new impeller, oil change and transmission fluid change. These won't help the speed but it's a good idea to start out the season. See what happens then. If it's still sluggish, dig deeper. I don't know anything about the Pro-Injection System but the electronic ignition conversion converts the distributor from points to electronic ignition. I wouldn't worry about it. Modern engines use electronic ignition to "tell" the plugs to fire. Older engines used points. Not a bad thing but you had to keep them adjusted, file the points down and check the gap--a lot of people, including myself, consider it a pain. |
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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Okay,
I changed all the plugs to Autolite 24's gapped at .035, and I replaced the cap & rotor. I also realized that there was an adjustment on the fuel injection control module that was a ways off from the notes of the PO. With all that changed, I headed out to the lake today. I still topped out at 36 mph turning about 3400 RPM. When the boat is in neutral, it will rev up to 4-5,000 RPM, but not under load. It also will bog down at times in neutral...only revving all the way up every 2nd or 3rd rev. Acceleration out of the hole doesn't seem too great either. Could it simply be a little water in the gas or a clogged fuel filter? I'm thinking of changing the filter out tonight. Any further advice is appreciated. Thanks!! Travis |
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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anthonylizardi
Gold Member Joined: July-25-2007 Location: DFW, TX, USA Status: Offline Points: 836 |
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That prop doesn't sound correct. I have an 87 1:1 transmission. I have 3 blade, 13" prop. Is an ACME 540. When I got my boat I had a 4 blade but it was the wrong size and would not rev more than 3600rpm. Let's see what the pros said.
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21136 |
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Im not sure if the prop is optimal, but the speed vs. RPM is pretty close to 1:1, so its in the ballpark. I think he has other problems- most likely fuel related.
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anthonylizardi
Gold Member Joined: July-25-2007 Location: DFW, TX, USA Status: Offline Points: 836 |
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Are you sure? I believe I had 1442 which is close and my boat was a hog. It ran fine but it didn't pass 3600rpm. I don't know anything about prop. It was your recomendation to buy the 540 which I am really happy with it.
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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I certainly think it's a fuel problem. I changed the fuel filter and added some Seafoam...then headed back out to the lake this evening. Still have the same problem. Running about 3300 RPM and 35-36 MPH. The last 3-4" of the throttle do nothing in gear. In neutral, the motor will rev up to 5000 RPM but won't hold it...it cuts down to about 3000. In gear, it won't do any better than 3300 RPM. I'm not concerned about the prop because of the way it acts in neutral. I've tried adjusting the Holley fuel injection but no solution. I'm stumped.
I did find one bolt of the 4 that attach the throttle body to the intake...it seems to be stripped out. Would that one bolt cause enough air draw to cause this problem? I'm running out of ideas. |
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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jimbo
Senior Member Joined: September-07-2004 Location: United States Status: Offline Points: 473 |
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Do you have a timing light? I'd check the timing at idle and around 3500 rpms. That stripped bolt is going to be a problem but I don't think it's the problem.
Unfortunately i don't know enough about your fuel system to be of much help. Is there any chance you've got an exhaust leak? |
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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I don't have a timing light...I'll have to find one to borrow. I can have the stripped bolt repaired in time, but I want to get it running right first. Funny you ask about the exhaust...there is a broken exhaust manifold gasket on one side clicking away. I didn't figure that would have anything to do with the performance...just annoying.
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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jimbo
Senior Member Joined: September-07-2004 Location: United States Status: Offline Points: 473 |
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My thinking is the exhaust gas leaking into the engine compartment is getting sucked back into the engine and it's not getting enough air. Try running with the hatch open or removed and see if it helps. Just be careful (make sure nothing can fly into the turning belts).
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
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check the anti-shipon valve at the tank where the fuel line connects to it.
Try running off of a gas can instead of the tank and see what it does, doing this eliminates the anti-shipon valve, vent and pick-up as causes. I'm a little puzzled you say in neutral it revs to 5k but won't hold, does it go up then stay's steady at a lower RPM with the throttle in the same position? meaning going wot, the RPM peaks then backs off on it's own to a lower RPM? what does the spray pattern from the throttle body look like? even cone shaped spray from all injectors? |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21136 |
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^^^I think '79 is on the right track here^^^^
If Im not mistaken, you had a 422, which at 12.5x15.5 is nowhere "close" to the 540 (13x12) or the stock 13x13. You had to be underturning by close to 600-1000 RPM, which caused the poor performance. (IE, at 3600 RPM you were not going anywhere near 36mph- probably closer to 42.) Travis is seeing ~36mph at 3400 RPM... so he's fairly close to 1:1. He's under-rev'ing a little, but that alone wouldnt account for his lack of performance. |
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jimbo
Senior Member Joined: September-07-2004 Location: United States Status: Offline Points: 473 |
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Are you really recommending flying down the lake at 35 mph with the fuel line stuck in an open can of gasoline??? Now THAT'S not Coast Guard Approved. I understand what you are trying to accomplish but that has the making of a Three Stooges episode. It would be a better idea to visually inspect those parts and clean them if needed. It's not that hard. You can do it in the driveway. Just expose the fuel tank, remove the pickup line, make sure it's clean (including the screen at the bottom. Also check the larger vent hose and through hull fitting for obstructions. You can also pull the tank out completely and drain it to rule out water in the fuel tank. I'd also change the fuel filter. It should be some oil filter looking device. I still think the exhaust leak is causing a good portion of your problems. |
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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Hi all, thanks for the feedback...I love the way this website works. Really helpful. I'm planning on trying many of the diagnostic checks mentioned above. I'll check the timing and see if I can eliminate the tank as a suspect. I posted another problem in another thread, and I'm wondering if there is a connection. I'm getting a STRONG smell of fuel from the boat at all times. I keep it in the garage and it has stunk up the whole garage and now it's stinking up the house as well. I've got to find what the problem is with that. I've searched for a leak from tank to throttle body and I haven't found anything significant that would equate to the smell. The only opening left is the vent...but surely this would not emit such strong fumes. I've owned 2 other boats and kept them in the same garage...never had this kind of smell from either. Could there be a connection there to my speed problem? Another note...I did take apart the brass elbow on top of the tank to the pick up. I expected to find the anti-siphon valve but only found an empty brass fitting. Is that a problem?
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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Looks like a very expensive tool...what is it? I wish my nose would work, but allergies are killing me. If I don't figure out this leak and get this smell out of the house...my wife may kill me first.
There are two fuel filters...one cheap plastic one before the electronic fuel pump (Holley Fuel Injection) and a normal metal filter after the fuel pump. I replaced the metal one. Is there any need for the cheap plastic one between the tank and the pump? I'm thinking about replacing that whole section with just a solid new fuel line to the pump. Any thoughts? Has anyone else had excessive fumes from the vent, or no. The way it smells, you'd expect to find the bilge full of fuel...but that's not the case...dry as a bone. |
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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Hey 79,
To clarify the revving...I can rev up the motor in neutral to over 5000 RPM, but within a few seconds it will bog down to 3K or so and bounce around between 2500-3500 rpm. That makes me think it is a fuel delivery problem...like it has enough fuel to go at first, then gets starved. All of that variance takes place without moving the throttle from wide open or close to it. Under load, I don't even get one good rev...it can't get there. |
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Travis,
Did you buy the boat with these problems? What does the PO have to say or are you able to talk with him? That meter is a gas vapor detector. They come calibrated for different types of gases. |
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jimbo
Senior Member Joined: September-07-2004 Location: United States Status: Offline Points: 473 |
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I'm assuming the Pro-jection system is a way to convert from carb to fuel injection. Does it have an injector for each cylinder? Does it have a pressurized fuel rail? If so, you could have a leak along the fuel rail and as the pressure leaks down, it slowly sprays a mist of fuel out. And if there's a leak, it might be sucking air when you put the coal to it. Just a guess. I really don't know anything about that fuel system.
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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I didn't suspect these problems when I bought the boat. The PO dewinterized it and we took it out once for a water test before I bought it. It ran a little rough at first with the fogging oil, but eventually ran fine as far as I could tell. I didn't notice the fuel smell, but he was keeping it outside at that time. He had kept it in his garage previously until buying his newer boat. I haven't contacted him yet...I may have to look him up. He seemed like a very stand-up guy and I honestly don't think the boat had any issues that he was aware of at least.
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
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Your fuel pump is shot I would say or the pressure regulator is bad, it shouldn't be dropping in RPM so that is fuel related and the only issue.
the metal filter is the fuel and water seperator get a new and replace the old one, the plastic filter doesn't hurt but replace it with a new one to play it safe. You need to put a wrench to the fittings for all fuel lines leading to the throttle. Also look back at the tank for cracked hoses for the vent line as well as the fill tube. The anti-siphon feature is part of the fitting looks like a regular fitting but it's not. if you can see daylight through it make sure you removed the rght part, remove everything at the tank might be two fittings someone might have all ready removed it as well so double check everything. Can you post some pictures. do you have fuel pressure gage to verify that the fuel pump has issues? |
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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Hey all, I'm not getting anywhere. I've tried many different things. There is no anti-siphon valve in my fuel supply line, no screen at the bottom of the fuel pickup, runs the same on fresh gas...nothing I've tried seems to work. I can't find any reason for it to be starved for gas. Anyone know of a good inboard mechanic near Lawrence or the Kansas City area? I'm ready to just have someone go through the whole thing and get her going again. I normally do this sort of thing myself...but this one has me stumped.
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Travis,
I mentioned before thinking there were 3 CCfan members who had the ad on injection systems. 2 went back to carbs but I remember 1 did get his to run after many hours of playing around with it. Do a CCfan search (older than 6 months) and see what you come up with. Maybe you'll luck out and be able to talk to the owners. You said you have a manual. What does it have to say? Holley tech line? Finding a mechanic to take a look at the issue may be a problem. They may just walk away from the engine once they find out it's been modified. |
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travbo24
Newbie Joined: October-20-2009 Location: Fort Collins, C Status: Offline Points: 29 |
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I've left a message for the previous owner, but haven't heard back from him yet. I have the original carb, and I would put it back on...but I figure there's a reason he took it off and replaced with the injection. I found a bad plug wire today...replaced it but still have a problem. Every time I think I may have found it...I strike out. I may put some more time in on it tomorrow.
Thanks! |
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'88 Ski Nautique
‘02 Super Sport Nautique ‘93 Bass Tracker Pro17 ;) |
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hotboat
Gold Member Joined: March-28-2009 Location: Conn Lake Pa Status: Offline Points: 814 |
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Check that all cylinders have "fire". After engine is warmed up and still at an idle, wet your finger and touch each of the eight exhaust outlets where they come out of the head. I had a brand new autolite that didnt work one time and it took a liitle while to find it. That would put your performance numbers where they are and being the boat is new to you it can be hard detect in sound sometimes.
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Brian
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