Still has a knock

[VisionaryDan]

I have successfully complete all the recommended fixes under the left side cover. Starter bolts, balancer nut and driven gear nut and I still have a knocking sound after the engine warms up. When cold it's only barely noticable but after riding for a while it's much more obvious.

The bike just turned 20K and I have owned it from new. Always did regular oil changes and maintainance. My second bike, that I recently bought has 25k with absolutely no knock at all.

I unfortunately in the mid 80s ran Arco Graphite oil in the bike for a season or so. The dealer recommended to discontinue this because it was not approved for wet disk clutches. Could that have caused bearing damage?

I had a mechanic years ago tell me that the slight knocking was a rod bearing going but recently I thought it was more likely to be the starter clutch bolts.

If it were a rod bearing would it be worth fixing? I have split a case on a bike once before (2 stroke) but this seems to be a slightly bigger job than the old 250 Suzuki I rebuilt.

So do I ride it till it dies and make my second bike my main project?
What do you think?

Dan

[ProfessorRex]

I can't see how using a non-wet clutch oil could affect the bearings.  Yes it can ruin your clutch due to the presence of friction modifiers (graphite in this case) that will imbed in the clutch and cause it to slip (at a molecular level, graphite is like tiny ball bearings)

I think someone here replaced their bearings, I'm not sure, try a search.

-Rex
(Sorry if this wasn't super helpful, I didn't want you to feel ignored)

[dminor]

 ??? Dan,
   Did you have all the gears on the left side apart? If you did maybe you have the same noise that I had. Take the cover off and look at the cam chain gear, it has a spring damper on it. If the drive gear is installed backwards, it will make one HELL of a noise. Just pull the gear off and turn it around. I did it to mine, no noise still runs great.
Don

[VisionaryDan]

Don,

I didn't dissassemble the entire left side. I only took out the rotor nas tightened the balancer gear nut ant the driven gear nut. There didn't have a reason to remove the driven gear. Was there something else that I should have done while I had it apart?

Dan

[jasonm.]

SO you tightened the big 46mm nut. That's the big one that usually loosens. But there is a technique to doing it. One of the important things is to completely remove the nut. Clean all with brake clean then use red loctite. The trick is getting the proper torque without wrecking the key on the crank. Most don't have a 46mm socket. Also, It could be a rod bearing...

[YellowJacket!]

Have you checked your spark plug?  Elementry question but I have seen noting mentioned about it.

David

[VisionaryDan]

I used a 1 13/16", 3/4 drive socket (almost the same as 46mm). I tightened it as tight as I could with a large breaker bar. I got about 1/8th of a turn or so. If I tied to tighten anymore wrench would slip. 

Spark plug? Dave are you saying that it could be loose?

Dan

[YellowJacket!]

I'm thinking of preignition knock and ping kind of knock that you can get from a hotspot on a plug.
Are you talking more about a loud knock like banging on metal?

David

[VisionaryDan]

It's not a banging of metal.? It's almost like a loud valve tap. I 'm pretty sure I changed out the plugs since I got it running but I'll double check that. Although it had been making this sound the last time I had it running (a few years back).
It now seems to be getting louder.

I'm half thinking I should take off the left side cover and try tightening the 46mm bolt with the right socket, lock tight and a sledge. Either that or pickup that parts bike in DC and throw in the spare motor that comes with it but he doesn't know how many miles are on it and my wife is not thrilled about having another bike lying around.

I could take the bike to my friendly neighborhood Yamaha dealer and see if I can get a mechanic to give me a second opinion. How much they would know about a 23 year old bike is in question.?

Either way I probably should to get bike two on the road or be without a bike.

Dan

[Lucky]

The V's Engine is a bit "tappy" up top. you can hear it well with the stock exhaust.  Mac.s mask it pretty well... :)

You can use a mechanics stethiscope to help locate the noise. a long screwdriver will work too, but not as well.  hold the tip of the screwdriver to various points on the engine & put the handle against your ear.  You'll be surprised at all that you can hear.

You can do a valve adjustment if it hasn't been done, that may or may not help, but if you don't know how long it's been since it was done last, it's a good idea, even though it's a pain in the butt.

--Lucky

[Superfly]

Check you exhaust gaskets... sounds simple, but new ones really quieted my bike down.

[VisionaryDan]

Exhaust gaskets, that's worth a shot, I'll check it out.

Dan

[jasonm.]

I had an exhaust leak. It sounded more like spitting. ALSO, you just can't go get a 46mm and go crazy. The book actually tells you to also remove the right side cover and put something between the primary gears. Just removing the left cover and wrenching puts a lot of force on the 2 keys in the balance system instead of just on the crackshaft when doing it by the book. OR you take a chance of shearing that key on the crank. Or screwing up the timing of the balancer. I think I am one of the few that has done it by the book. Mostly because I saw a picture posted of a sheared key. Don't forget the torque wrench. ;D Good luck...

[VisionaryDan]

I tightened all my exhaust fittings - no change
I also put in ne plugs - no change

I tried the screw driver stethiscope thing - I still can't pin point it. I had my 23 year old son with better ears try and he can't seem to find where it's coming from either.  But it's definitely getting louder.

I'll get the dealer to look at it.

It's a shame, otherwise the bike is running better than ever. No stumble, idles well and accelerates great.

Dan

[Coil Coyle]

Dan,
         Are the valve clearances OK? ???

I don't see anything about when you last set the tappet's shims.

coil

[VisionaryDan]

It's been a while but you think if it was valve clearance that it would the tapping would exist whether the motor was warm or cold. It only make the noise when it's warm.

Could it be from having my the fuel mixture too lean, causing a ping at an idle? At higher RPMs I can't seem to hear it although other motor noises may just be drowning it out.

Dan

[Lucky]

it could still be valve clearance even if it only does it warm.  metal expands as it heats up...

[VisionaryDan]

Well I took off the afternoon and took the "V" to the dealer where I bought it almost 22 years ago. The mechanic said the noise is definately in the top end. After he got a second opinon they both said cam chain adjuster is shot. Actually both cam chain adusters need replacing.

Anyone else out there have to replace these guys? $153.00 plus tax for the two of them and gaskets. I plan to take them out and check them out before ordering or maybe swap them from my other bike to see if anything changes.


I'll let you know if they are right.

Dan

[Coil Coyle]

Dan,
Change the chains too!
coil

[VisionaryDan]

Coil,

I can't find anything wrong with the adjusters. Would it be normal maintenance for you swap out the chains at 20K? 

Dan