Cam Chain Noise

[Ed Mackessy]

Hi Guys,
I wrote in last month about checking my cam chain tensioners. I pulled them out and they seem to be ok. When I retract them and then pull out the screw driver, they snap out. I put them back in, without setting the pistons at TDC and the bike still is making the same rattle sound in the top end. It does not start to make this noise until it is warmed up, and it starts at 3500 RPM. Just to add to the fun, the noise seems to be intermittent, but, more often than not I can hear it. It seems to be in the fromt cylinder set.

Could I have a weak spring in the tensioner?? Should I just replace the tensioner and see what happens?

The dealer wants me to write him a blank check so he can go exploring in the motor of my bike. They hear the noise but don't know what it is. That makes me think I don't want them to touch it. Any Ideas?? Thanks.

[silveradocowboy]

What year model is it?

[Magnum Magna]

I agree with you they don't instill a lot of confidence.

I loved that old TV commercial. I always wanted to work on a Transmissiooon.  

[Ed Mackessy]

Sorry about leaving out the bike info.
It's a 2003 VF750C with 21,700 miles on it. I ride it with out beating on it.
Once in a while I open it up and enjoy the thrill, but it wants to go faster than I do.

[silveradocowboy]

Well if it had been a 1st gen I would have said it may be a bad spring on the cam tensioner or valves needing adjustment. Several other folks here have more knowledge on the 3G's than I do so I'm sure they will chime in.

[Instructor50]

It wouldn't by chance happen only in first would it...and sound like someone is jingling change in their hand huh?

IF SO, that's the same thing I'm hearing from mine now too.

I have a 1996 VF750 and it hasn't always had that noise.  I'm just curious if that's what you are hearing too.

Brandon
Instructor50
USAF

[Ed Mackessy]

No, I hear it in all gears, including nuetral, with or without the clutch engaged. When the bike is cold I do not hear it, after a mile or two it starts to rattle at 3500 rpms, sounds like a loose cam chain, but I have checked that and they seem ok. In nuetral, if you goose the throttle and let go I can hear a rattle as the engine returns to normal idle. I had the valves checked at the dealer. That turned out to be a waste of money. Valves were "within spec." and the bill was over $200 bucks.
Still searching for the problem.

[Greg Cothern]

What oil are you running Ed???

[Ed Mackessy]

Hey Instructor 50,
After re-reading your reply I remembered that when I started to look for my mystery noise, I found a loose chrome cap that fits over the nut on the swing arm pivot point. It rattled around at rev's sounding just like loose change. I could not get the cap off so I used a little clear silicone adhesive and forced it into the gap with my finger. That locked the cap down and stopped the loose change sound. It was on the left side of the bike. Hope this helps.

[Ed Mackessy]

Hi Greg,
I am running Amsoil 10W 40.

[Greg Cothern]

Is it the Amsoil motorcycle synthetic???

Reason I ask is some non motorcycle specific oils have different detergents and some contain friction modifiers which make our clutches not work properly.

Not sure if it would cause you noise or not but worth a check.

[Ed Mackessy]

Hi Greg,
Yes the Amsoil is a full synthetic. I am not getting any clutch slippage and the noise was present prior to changing to full synthetic.

Do you think going to a 20W 50 grade may help?? I almost suspect that the noise is not in the engine at all, but a heat shield of some kind that loosens up when the motor heats up. A loose cam chain would make the noise hot or cold but my mystery noise only happens when the motor warms up.
It's cold in NY today (59 degrees) and I took the bike out to see what happened. Sure enough, the noise took a lot longer to manifest itself.

I have checked the chrome muffler covers and they are tight.
Is there any type of metal shield up under the gas tank or at the top of the front jugs that could be vibrating after warm up? I have checked the chrome covers on the top of the cylindrs as well.

[Greg Cothern]

I have long thought maybe a slightly heavier oil meaning 20w vs 10w would help in the hotter climates such as Texas.

[Instructor50]

Ed,

Thanks for the info. on the "loose change" sound.  I'll look into it in more depth.

Thanks,

Brandon
Instructor50