Exhaust or Engine Clapping noise?

[VentureBob]

1985 VR, started hearing a clappy noise at start up and would quiet down after warmed up. i thought it was the "H" Pipe rattle eveyone complaines about and since it was the end of the season I didnt think too much of it. However I have been going to start the bike up at least once a month and letting it reach operating temp before shutting down. This last time I was starting think maybe my clappy noise was engine related and not exhaust. Below is a link to the video I just shot from a cold start and walk around trying to see if I could pin point where the clappy noise was comming from. I am hoping someone here with more experience is able to recognize the sound and tell me if it's exhaust or engine. I am hopping for exhaust as I plan on doing the HD muffler MOD and weld up the "H" pipe in the early spring.

 

Thanks for your help. please use the link below to see the youtube video.

 

[ame=http://www.youtube.com/watch?v=w9CczUTzayg]YouTube - VID00001[/ame]

[dingy]

I think some of the noise is valve train related. Mine still has somewhat similar noise when first started, but not quite as pronounced, but may be due to sound recording. It was gone through completely, 6000 miles ago.

 

Smoke on right bank is much worse than left bank, possible valve stem seals.

 

How long has it been since valves checked?

 

Have you done a compression check, probably won't show anything, but would point to valve stem seals for smoking.

 

Some what of a miss when first started up, while choke engaged. Might as well hear it now, cause your gonna hear it later, Seafoam.

 

Radiator bypass valve looks to be in wrong position slightly.

 

Gary

[bkuhr]

kudos to making video

no expert but sounds to me like 1 cylinder not firing or dropping spark

[VentureBob]

I think some of the noise is valve train related. Mine still has somewhat similar noise when first started, but not quite as pronounced, but may be due to sound recording. It was gone through completely, 6000 miles ago.

 

Smoke on right bank is much worse than left bank, possible valve stem seals.

 

How long has it been since valves checked?

 

Have you done a compression check, probably won't show anything, but would point to valve stem seals for smoking.

 

Some what of a miss when first started up, while choke engaged. Might as well hear it now, cause your gonna hear it later, Seafoam.

 

Radiator bypass valve looks to be in wrong position slightly.

 

Gary

 

I knew after posting this video you guys would see other things that may be wrong . Dingy, that is not actual smoke comming out of exhaust. its cold outside and when it gets warmed up like a cold car that goes away.

 

Valves were adjust by P.O less than 5k miles ago. I have the work order from the shop from P.O and he put over $1700 into the bike at 86223 miles and I just turned it 90k before parking for the winter.

 

As far as Seafoam goes, I am an advid user in my vehicles, lawn & garden equipment as well as the bike. This past summer I ran 1/2 can for every tank of gas for at least 4 tank fulls.

She starts a bit hard when cold and stinky when running and I am pretty sure running a bit rich. I do have plans to do Skydoc's shim mod and new diaphrams and do a carb sync before spring but now if this is actual engine clapping noise and not exhaust I am not sure its worth me sinking money into it. I am not skilled enough nor do I have the tools to rebuild the engine and at this time not a lot of extra cash to toss at it either. I was saving for the few things I thought I could do from reading here on the boards and hoping for another summer of justing riding.

[SC89Venture]

Well, hell I am depressed now. Yours sounds pretty darn good, where is all the spitting / popping / farts / backfire sounds like mine does? At least mine does all that for the first 10 minutes until it warms up and then calms down.

[BOO]

I'm no expert either but the engine sounds pretty good to me.

Sounds like something going on in one of the cylinders but I don't think it's mechanical.

Sounds more like firing or fuel issue.

I do hear the sound but it don't sound serious.

BOO

[dingy]

If it were the cold air and normal exhaust condensation, I would think the two sides would be the same.

 

The right side looked much denser than the left. This could be a sign that the right and left side are not at equal operating temperatures, hence not firing on all cylinders as Bkuhr suggested.

 

If you could check the temperatures of the individual cylinders when you first start it, this may give you a clue as to which one, if any are not firing.

 

Your bike looks nice, considering its 26 years old. I would check the drain valve though. Look at thread linked below. Snaggletooth posted pictures of position it should be in. You need to click on pics to see full size version to appreciate the positioning.

 

http://www.venturerider.org/forum/showthread.php?t=55914

 

Gary

[MiCarl]

I agree with Dingy, sounds like mostly valve train noise. I noticed that there also what sounded like an exhaust leak when you were low on the left side.

 

I wonder if the difference in appearance of "smoke" from the mufflers is that the right one is open more, with the gas moving slower.

[Dano]

When is the last time the oil was changed and what type was he running in there? That could contribute to some low top end oil pressures if it was old and thin one might think.

[VentureBob]

I changed the oil and filter last spring and used yamalube I think it was called. It was what the dealer recommended. I read lots of controversy over motor oil on these forums and just decided to ask the shop that had been taking care of the bike for the past 86k miles what they used.

 

I have a friend helping me with some of the repairs and he read about doing something with the exhaust tips and what you see is the results. I was not happy but nothing I could do about it either. My will to just ride out weighed the looks and sound of ruined exhaust this last summer. I always thought that having the larger opening on the right side was causing some imbalance of back pressure and that is why the HD muffler MOD is first on my list.

 

I know there are two places on the left side that sputter exhaust from the joints. If it is decided that this is not a major mechanical failure going on I will be doing skydoc needle and shim MOD with new diaphragms and getting carbs synced. I will also be changing out plugs. Also on the list of things to do is replacing the diodes of the TCI and relocating.

 

I like the fact that this is an old bike and I always get compliments while I am out and about. I do like to tinker around but I am not much to major rebuilds or overhauling.

 

Hey Gary, you mentioned that I should check the temps to see if there was any cylinders not firing, is that the start it up when cold and let it run for 10-20 seconds and shut it down then feel the header pipes test?

[dingy]

That would be one way. If you know someone that has an infrared theromometer, you can check temps as it reachs operating temp. This would assist a little in diagnosing if temps varied widely. The IR temp reading will vary depending on where reading is taken at. I found it fairly consistent on header flange that bolts to head.

You may need to pull side covers to get to rear headers.

FYI, these can reach temps of 400 F. and up somewhat quickly.

Gary

[Yammer Dan]

Maybe a little leak at the ring clamps on rear headers? I really couldn't hear anything but those clamps seem to work loose sometimes. I pulled mine off and ground the ears down on them so it would tighten. The ears keep them from closing. They will leak when cold and as the metal heats up it slows the leak down. Grinding the ears off help to tighten the clamps.

 

I listened to it again. Check those rear headers when it is cold. Just wrap your fingers around where they clamp togather. I'd bet on a leak. Careful they get hot very quick. Pull side panels before you start.

Edited January 20, 2011 by Yammer Dan

[jimmyenglish]

I'm with YammerDan. One of the rear exhausts on our 86' has a manifold leak. Really easy to confuse with valve train noise. First time I heard it I got real paranoid. Already done the collector fix. The noise is so subtle and I'm just too lazy to get into the rear headers. Will live with for now. Yours sounds like a good running motor to me!

Edited July 11, 2012 by jimmyenglish