351 ENGINE INITIAL TIMING???
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=10382
Printed Date: May-18-2024 at 4:01pm
Topic: 351 ENGINE INITIAL TIMING???
Posted By: 76'SN
Subject: 351 ENGINE INITIAL TIMING???
Date Posted: May-04-2008 at 11:03pm
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i seem to be having trouble maintaining a set time on my engine. i set the initial timing to 10 degrees but after i run the boat it is way off, to the point where it wont idle in gear and still runs rough out of gear. engine is at idle (about 600rpm) when timing is set and distributer set screw is tightened after setting time and is not moving. where and what should i be looking for to correct this? just recently began happening. thanks ------------- hukt on fonix helpt me |
Replies:
Posted By: boat dr
Date Posted: May-04-2008 at 11:26pm
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Sounds like a new timing chain and gear set are in your future.An easy test is pull the dist. cap and roll the motor backwards. the rotor should turn as soon as you roll the motor . Any lag will tell you the degree of slop in the chain,,,,,,,,,,,
Boat dr ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: 76'SN
Date Posted: May-05-2008 at 11:30am
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makes sense. i will try that this afternoon and let you know what happens. thanks for the fast response ------------- hukt on fonix helpt me |
Posted By: 81nautique
Date Posted: May-05-2008 at 11:52am
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Is it off permanently or does it fluctuate back and forth? Could just need new advance springs. If the springs are worn out or plates sticking the advance may not be returning to your 10 initial. ------------- You can’t change the wind but you can adjust your sails |
Posted By: 76'SN
Date Posted: May-05-2008 at 12:13pm
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right. i actually planned on replacing cap, rotor, and points so i may as well check that while im in there. i revved it up several times with no load on it while watching the timing light and it seemed to return to normal, but i only revved it once or twice while watching. thanks for the input, ill definitely check that out! ------------- hukt on fonix helpt me |
Posted By: 79nautique
Date Posted: May-05-2008 at 12:31pm
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I'm at a lost for the set screw you are talking about. There should be a bolt holding the clamp to the manifold that holds the dist in place rotationally. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 76'SN
Date Posted: May-05-2008 at 12:37pm
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im sorry, thats what i was referring to. ------------- hukt on fonix helpt me |
Posted By: 76'SN
Date Posted: May-05-2008 at 9:44pm
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i popped the cap on the distributer and turned motor over backwards while watching rotor. rotor did not move immediately. i got a hair or so turn on the wrench before it moved. is this satisfactory? also, should i be able to move rotor back and forth in a rotational motion with my hand about an eighth of and inch or so both ways? ------------- hukt on fonix helpt me |
Posted By: boat dr
Date Posted: May-05-2008 at 10:37pm
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Any slack tells me there is wear or slack in the timing chain. How many hours on the clock?
The rotational slack you are feeling on the rotor is normal, not to be alarmed by this.... You have said you were moving the distr. to retime it , are you losing advance each time ? Meaning if you set it at 6 degrees and later checked it were you back at 1 or 2 or even less????? This will indicate a slippage at the timing chain or possibly the drive gear of the distr. Just some food for thought.......Boat dr ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: 76'SN
Date Posted: May-05-2008 at 11:15pm
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yes.. i set the time at 10 degrees and after running it the time is around 5 or so. what would be the best course of action to take at this point? ------------- hukt on fonix helpt me |
Posted By: boat dr
Date Posted: May-05-2008 at 11:48pm
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My first impression would be the timing chain, but just for giggles pull the distr, and check the drive gear. If that is not the culprit then step B is remove the front cover.
A double row timing chain and sprockets are the only way to go. Sumitt brand is just as good a deal.An afternoon and a hundred bucks should give you a rock steady timing base......Boat dr ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: 81nautique
Date Posted: May-06-2008 at 12:19am
That doesn't make any sense, you're saying that everytime you run the engine the chain is stretching 5 degrees. I don't see how that can be unless it's totally trash and I think you'ld see more movement when you checked it earlier if it was. I still would check the distributor first like boat dr says, could be the pin that holds the gear on is worn or broken and the gear is moving enough to throw your timing off. If the dist checks out then throw a good chain on it. ------------- You can’t change the wind but you can adjust your sails |
76'SN wrote:Posted By: boat dr
Date Posted: May-06-2008 at 12:26am
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Allen take a look at you timing marks, see how close the little marks are? Now try to imagine 5 degrees of rotation, aint much is it. A double row wont do it but the old stlye surely will, been there done that.....Boat dr ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: 76'SN
Date Posted: May-06-2008 at 12:46am
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should bother checking the advance spring? i really didnt want to unless necessary simply because of all of the parts removal to get to it. but more than likely a new timing chain and gears would correct this problem, right? ------------- hukt on fonix helpt me |
Posted By: 81nautique
Date Posted: May-06-2008 at 12:47am
Agreed, a timing chain will stretch but if it's growing at that rate it's no longer stretching it's breaking. Won't be long before it jumps a tooth, the factory gears are usually nylon and probably giving up too. I'd be inclined to invest a hundred bucks and a few hours and change it right now. ------------- You can’t change the wind but you can adjust your sails |
Posted By: 76'SN
Date Posted: May-06-2008 at 12:52am
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also i meant to add, with this boat being a 76' is this safe to blame normal wear for this problem? i figured a chain would to a pretty good job of maintaining its setting. what would cause the drive gear to shear. didnt think there was enough play in them to get loose enough to wear. ------------- hukt on fonix helpt me |
Posted By: 76'SN
Date Posted: May-06-2008 at 12:55am
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alan, you mention the factory gears may be nylon. are the replacement gears be made of nylon as well? i dont mind investing the money. i am definitely going to check it out. is there a site where i can order this stuff? and is there any diff in a normal 351 gear and chain set since these motors are reverse rotating? ------------- hukt on fonix helpt me |
Posted By: 81nautique
Date Posted: May-06-2008 at 1:25am
Once again Summit is good for your gear set, I put a Cloyes in mine, don't have any experience with Summits set but most of their house brand items are made by the big guys anyway so it's probably fine. A good set will have steel gears, timing chain wear is a fact of life. I put 750 hours on a 351 PCM and thought it was dying, replaced the timing set and brought it back to life. Make sure you get your gasket set at Skidim not the local auto parts store. Call and tell them what you're doing and they'll set you up. ------------- You can’t change the wind but you can adjust your sails |
Posted By: 76'SN
Date Posted: May-06-2008 at 4:19am
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i plan on looking into that first thing in the morning and hopefully be running by this weekend! my hour meter quit working at 817hrs, and that was a few years ago. what gaskets should i need to go back together? i planned on getting them when i buy the chain and gears. ------------- hukt on fonix helpt me |
Posted By: 76'SN
Date Posted: May-06-2008 at 5:21am
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i found these two items from summit. cloyes chain and gear set along with timing cover gaskets. how does this look? should this get the job done and is this one the double row like you referring to?
http://store.summitracing.com/partdetail.asp?part=CLO%2D9%2D3535X9&view=32&N=700+150+4294840125&appfilter=1#Application and http://store.summitracing.com/partdetail.asp?part=FEL-TCS45008 ------------- hukt on fonix helpt me |
Posted By: 81nautique
Date Posted: May-06-2008 at 10:17am
I don't think that gasket set is going to work, call skidim and get PCM gaskets. Make sure you tell then you're replacing a chain as I think they'll need to get you an oil pan set. You'll need the front pan gasket and also need to cut the cork gaskets for the bottom corners of the pan gasket. Make sure you use some permatex in those bottom corners when putting it back together when putting. The cloyes is a good chain but little spendy, Take a look at all the options as I think you'd find a cheaper unit. ------------- You can’t change the wind but you can adjust your sails |
Posted By: 79nautique
Date Posted: May-06-2008 at 10:56am
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It sounds like the clamp holding the dist is screwed up and not working right.
Grap the whole dist cap and try rotating it if it moves then I'm right. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 76'SN
Date Posted: May-06-2008 at 1:26pm
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the distributer WILL NOT move once clamp is tightened. it is even hard to move if the clamp is finger tightened. how much should i expect spend on a good durable brand if gear sets and chain. im not trying to be cheap because i realize alot of times u get what you pay for and i dont want to go through this again. ------------- hukt on fonix helpt me |
Posted By: 79nautique
Date Posted: May-06-2008 at 1:34pm
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well if the chain is shot then everthing else isn't far behind so you might as well re-build the whole thing. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: JoeinNY
Date Posted: May-06-2008 at 1:45pm
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Any old 351w timing cover gasket set will work, you will need an oil pan gasket as well. Any old double roller timing gear and chain set will work as a replacement and probably last the rest of the life of the motor as you have significant hours at this point.
Either way your going to have to pull the distributor, so before jumping into it I would pull the dist and check the gear for wear. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: TRBenj
Date Posted: May-06-2008 at 1:47pm
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That timing set looks fine. A Comp or Crane double roller for ~$40 would probably work, but $85 for a Cloyes True Roller isnt bad- thats where my money would go. ------------- |
Posted By: 76'SN
Date Posted: May-06-2008 at 2:26pm
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jus pulled the distributor and no gear wear is to be seen. shaft and gear seemed to be very well oiled. pin is not twisted. if i hold the gear and turn the rotor with my other hand it has a springing action one way that moves almost 1/8in in that direction but springs back when i let go. is this normal? other than that all is good with the distributor. i talkted with my local nautique mechanic and he seemed to agree with the diagnosis. again i appreciate all of the input! ------------- hukt on fonix helpt me |
Posted By: JoeinNY
Date Posted: May-06-2008 at 4:20pm
Normal, thats just your centrifical advance thats why is only in one direction. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: 76'SN
Date Posted: May-06-2008 at 8:13pm
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ok. good deal. im working on get a gear set and chain together now and will let you all know what happens. ------------- hukt on fonix helpt me |
Posted By: 76'SN
Date Posted: May-06-2008 at 8:52pm
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am i going to need a puller to remove the harmonic balancer? i am picking up a cloye gear set and chain with all gaskets tomorrow. ------------- hukt on fonix helpt me |
Posted By: Barracuda
Date Posted: May-06-2008 at 11:21pm
Yes, you're going to need a puller to get the harmonic balancer off. If you don't have one or can't borrow one from a neighbor, try the rental section at your local auto parts store. Just throwing this out as one more thing to check before you go tearing into it- Check the distributor shaft end play with a feeler gauge. Compare it specs for that dist (don't have the spec handy). If there is too much play, then the timing will vary as the shaft rides up and down on the tapered drive gear. Good luck -Brad ------------- Former: http://www.correctcraftfan.com/diaries/details.asp?ID=759" rel="nofollow - '86 Nautique http://www.correctcraftfan.com/diaries/details.asp?ID=507" rel="nofollow - '65 Barracuda |
Posted By: 76'SN
Date Posted: May-07-2008 at 2:35am
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ok i will check that out. i went through the check list with that distributor today once i removed it. everything seemed normal. i cant recall an alarming amount of end play. i wiggled just bout every part one way or another checking for anything such as that. on the timing chain, there aren't going to be any curve balls thrown at me once i dive into that are there? the crank gear is a 3 piece keyway. i was also warned about chain clearance with it being a double row. what are the chances i will have to grind anything on the block to make way? ------------- hukt on fonix helpt me |
Posted By: 76'SN
Date Posted: May-07-2008 at 5:11am
this is what i have so far. i pulled cover and saw that i had a some play in the chain. the first pic is just as it sits and the second is showing the amount of play in the chain which seems to be quiet a bit. probably a 1/2in or so.
 ------------- hukt on fonix helpt me |
Posted By: GottaSki
Date Posted: May-07-2008 at 11:58am
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Seen worse, I don't think thats your problem. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: JoeinNY
Date Posted: May-07-2008 at 12:27pm
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Unfortunately I tend to agree although hard to tell from the picts. In my experience you typically have serious teeth wear before it effects timing enough to cause running issues. Here is where I would put the balancer bolt back in and then turn the engine over and look for any lag in movement between the cam and the crank. In my experience you typically have serious teeth wear before it effects timing enough to cause running issues. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: gigem75
Date Posted: May-07-2008 at 12:35pm
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The one I'm doing now has worse than that on each side! I agree that is probably not your problem. I also agree with 79 that if you have serious wear on the chain everything else is not far behind. What is your oil pressure at idle when the oil all the way up to temp?
You said this just started happening. If it was chain wear it would have been gradually getting worse over time. Have you put a timing light on and watched how the advance comes up and back down as the engine revs and comes back to idle under the strobe? |
Posted By: 76'SN
Date Posted: May-07-2008 at 4:02pm
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i have put a timing light on it and watched. the timing advances and returns to initial with no load. it seems after i run it with a load, it runs fine long enough to plane then runs sluggish. i havent paid attention to my oil pressure because i think my guage is broke. ever since i got it, it stays around 75-80lbs under any condition (idle-WOT). ------------- hukt on fonix helpt me |
Posted By: 76'SN
Date Posted: May-07-2008 at 4:06pm
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if its not the timing chain or distributer then what else could could be the culprit for my problem? ------------- hukt on fonix helpt me |
Posted By: 79nautique
Date Posted: May-07-2008 at 4:08pm
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well I would say you need to look at the advance weights again and pay close attention to the springs and how freely the weights move? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: JoeinNY
Date Posted: May-07-2008 at 4:10pm
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The last description sounds like a carb issue. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: 79nautique
Date Posted: May-07-2008 at 4:15pm
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are you setting the timing when the engine is at 600-700 rpm? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 76'SN
Date Posted: May-07-2008 at 4:26pm
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yes. my idle is a little over 600. would it be a bad idea to go ahead and replace the chain and all while im in there? and is there any trick to removing the gears or do they just slide on and off? ------------- hukt on fonix helpt me |
Posted By: 79nautique
Date Posted: May-07-2008 at 4:43pm
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well I would suggest that you spin it around untill the dots on the two gears are lined up vertically. Once that is done then unbolt and slide both off at the same time, then align the dots on the new gears with the chain on them and slide it onto the crank and cam.
usually you can start the bottom gear a little then slide the chain over it while you are holding the top gear in the proper alignment then slide them on the rest of the way, too hard but make sure you get them lined up properly. There should be an instruction sheet in with the new gear and chain so review that as a reference for detailed info. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 76'SN
Date Posted: May-07-2008 at 8:48pm
i installed new chain today and timed engine. runs great on trailer. i expect to take it to the lake sometime this weekend and see how it works out. im praying this fixed it!
 ------------- hukt on fonix helpt me |
Posted By: David F
Date Posted: May-09-2008 at 4:39pm
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I am sorry, but I was too lazy to read all the posts. I think the original chain was fine, but since you opened it up, no harm in changing it. How many years/hours on the engine? My quess is that you need to pull the distributor and replace it. Save the gear. ------------- |
Posted By: 76'SN
Date Posted: May-09-2008 at 10:11pm
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thats kinda what i was thinking as well. its a 76' model with maybe 1200hrs on the motor. guage stoped at around 800 sumthing. i will probably replace distributer as well. i am trying to eliminate ANY possible problems for when i take it out. nothing blows worse than being stranded on the water with all ur buddys. buzz kill!! would a set of new points and condenser as well as cap help or just replace the whole thing. i have a kit already if it would be worth it. thanks for the input. ------------- hukt on fonix helpt me |
Posted By: eric lavine
Date Posted: May-09-2008 at 11:21pm
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if you can check all bolts on the intake and maybe put a vacuum guage on it, with this you should see a miniumum of 18 inches of vacuum, it was good that you did take the time to do the chain and your on the right track and converting over to electronic will also help. a good way besides spraying starter fluid around the intake to check for leaks is a paint stick soaked in charcoal fluid, you light the stick and then blow it out and it gives off real good white smoke and if leaking will pull the smoke in by the leak. these are simple tests and if problem continues a compression test wouldnt be a bad idea either if all other attempts to repair dont cure the problem ------------- "the things you own will start to own you" |
Posted By: Luchog
Date Posted: January-30-2009 at 12:12pm
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problem solved??? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique Commander 351W |
Posted By: Waterdog
Date Posted: January-30-2009 at 3:48pm
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When you set the timing ,double check it AFTER the distributor is tightened down.The timing WILL change several degrees after the distributor is snuged down! It drives the 2 gears into a tighter mesh. ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: 8122pbrainard
Date Posted: January-31-2009 at 11:20am
Andy, Please explain - I must be missing something! The gears are straight bevels. The only way to bring them into a "tighter mesh" is to decrease the distance between the cam and distributor shaft centerlines. This distance is a set dimension matching the pitch diameters of the gears by the bore locations in the block. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Waterdog
Date Posted: January-31-2009 at 1:29pm
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Double post ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: Waterdog
Date Posted: January-31-2009 at 1:31pm
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Pete
When the distributor is loose enough to rotate it, the gears "ride up" a little , thus moving the distributor out of the hole. You never double checked the timing setting after snuging the distributor down? It does change. Hope I explained it. ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: 8122pbrainard
Date Posted: January-31-2009 at 2:11pm
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Andy,
Yes I always double check the timing after tightening down the distributor. "Ride up" is different than "tighter mesh". Ride up is the normal backlash (clearance between the gear teeth) built into the gearing with the machining tolerances. "Tighter mesh" would be like shimming the pinion gear depth for backlash on the spiral bevel gearing in a differential. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |