Cam Chain

[RobTx]

The weather was nice today, so I went for a ride.  About 20 miles.  My exhaust is seriously rusted and I had a better one I bought on ebay, so I decided to replace my rusty one when I got home.  Now it's so quiet I can hear some noise in the front cylinder area.  It's either valves or the cam chain.  It's sounds like tappet noise, but I know the Vision uses shims.  What does too much clearance sound like with shims?  The noise seems to disappear when I rev the engine.  I'm thinking the cam chain tensioner needs adjusting.  What is the procedure?  I don't own either manual, but I'm looking. Shouldn't be too hard, loosen a lock nut, turn adjuster, tighten lock nut?  I ran out of daylight, I'll look at it tomorrow.  Thanks.
Rob

[Dave T.]

At least it's in the the front cylinder (less of a pain to service). Cam chain tensioning is automatic. The spring in the tensioner may me past a wear limit (measure with a caliper). I don't know if there is a value for this. Maybe the plunger is stuck. It's easy to check though. Just remove the center bolt, then the 2 bolts on the outside. Push in the "check plunger", put the 2 bolts, then put back the center bolt with spring to install.

I would guess a sticky valve, or poor seating of a valve. Floating as you rev the engine may be causing the noise to go away. Excessive clearance may be the cause too. It's not too difficult to check. Changing shims is a little tougher though. I think you are in for some engine work.  :P

[Kenny]

Hi Rob,
      Just a thought-have you done the starter clutch bolt mod? Info is in Lucky's site under "Engine & Drivetrain".
    I could of sworn the noise on mine was from the top end.One way you can isolate the noise is to use a rod or long screwdriver with your ear to one end and the other on the suspect location.
  Do you know when your valves were last set?
     Good luck finding this noise.
          Cheers Ken S  

[RobTx]

Kenny,
I've done the starter clutch mod already.  The noise is very subtle, like I said, the exhaust was so loud before I never noticed it.  It was cold today, so I will try to adjust the cam chain tomorrow and see if that makes a difference.  
Rob

[jasonm.]

If it's a "ticking"? It's either a shim that needs to be replaced on the top of the valve. OR the balancer drive gear. This gear is on a small key behind the flywheel. This gear tips back and forth at idle. The bike can go many miles like this with no harm. Hopefully it's the valve shims. Which are easier to mess with when you have the right tools. Since you say it's the front. I would bet on a shim.

[Lucky]

I have always found the V's engine more 'tinny' or rattly than I prefer, in fact, it used to make me nervous until I heard Glen's 83, he had just had the valves adjusted, and it sounded just the same.  Keep in mind that aren't hydralic lifeters, so it's bound to be noisyer.  it's really my only complaint about the bike, how it sounds, exhaust & engine wise.

Also, Kwenny, the chains have automatic adjusters, so there isn't anything to adjust, but you can check to be sure everything is tight & not too worn, broken, etc.
--Lucky

[Cdnlouie]

Hey Rob us Yankees & Canucks really feel for ya riding around in all that sun and warmth.  However, if we can live vicariously through you it is nice to know there is a Vision prowling around somewhere.

Usually the valve shims get tight with wear and of course that is the silent killer. You may be hearing as Lucky said the normal engine noise.  You might think about the weight oil you are using.  If it gets hot your fall oil might be a little too light and generate a bit more noise.

If all else fails the Shoei RF900 has nice sound prevention, it really helps with my MAC pipe.

Still shoveling snow,

Louie  :(

[RobTx]

Hey Louie,
70's and sunny here today, but I'll be watching the first of the Daytona races on Speed Channel this afternoon.  Maybe a ride after that with my girlfriend.  Nice to have a significant other that rides.  I changed oil when I did the starter clutch and used 20w-50.  I'll get out and check the cam chain later today and the valves tomorrow.  What are the clearances on the valves anyway?  Measured hot or cold?  Inquiring minds want to know!  Sunny for the whole weekend, so I might just ride instead and worry about it later.  The noise is subtle and much quieter than my gf's xs650, man that thing makes a LOT of valve noise!
Rob

[Cdnlouie]

Make sure the feeler gauges have a slight drag to get an accurate reading. ?It should lightly pull against you as you withdraw the gauge. ?A light pull is perfect adjustment and not in need of changing.

The valve clearances are:

0.11-0.15mm or 0.0043-0.0059 inches for the intake (engine cold).
0.16-0.20mm or 0.0063-0.0079 for the exhaust valve.

Check with your local Yamaha dealer to see if they will do an exchange (for the same price as a new one at least, some guys are nice and don't charge, others add 100% mark up). ?New shims are available from Yamaha. ?You may have to change about one shim per cylinder.

Enjoy your bike date,

Louie  ;)

[jasonm.]

Yes, the shims can tighten up. On my '82 almost every shim was too tight. With only 5k miles this was strange. But easily solved. My '83 at 12k had only 2 shims out. They were loose. So anything is possible upstairs.