TOPIC:

I have used a simplex typr cam chain in my 650 in the past but have recently changed cranks and the one that I am using now is the hyvo type, I find that the valve train is much noisier with the hyvo chain has anyone else noticed this?

I don't know why the valve train would be noisier, the hyvo chain is supposed to be quieter than the roller chain.
You did use the hyvo cam sprockets and chain guides. right?

Hmm,after reading your sig, it's doubtful you would have made a mistake like that

Post edited by: steell, at: 2006/05/12 12:36

HI Steell, yep chamged the sprockets and all the chain guides and also the tensioners (changed the cam chain tensioner to an 82 GPZ750 wedge type) and the head with the rubber piece in the cam cover to an automatic one from an '82 GPZ750. You dont notice it when the motor is warming up but it makes a bit more noise when warm. I guess next time I am at the z owners club gathering I will have a listen if I hear the same difference between an older model annd a newer one with the hyvo chain

Ah yes, now I remember
IIRC, you are running a megasquirt on there?
I'm impressed with what you have done to the bike, how long have you been working on it?

Back on topic, I really don't understand why the HyVo chain is noisier than the roller chain, at one time the HyVo chain design was advertised as the "Silent Chain" due to it being much quieter than the roller chains.

The primary drive is the same type of chain, and the only time it gets noisey is when it has stretched and gets slack in it. That leads to the conclusion that if the cam chain is making noise, then it is to loose, and if it is to loose then the chain tensioner is not doing it's job.

So it seems to me like it's time to take the tensioner off and take another look at it.

Yes thats my 650 that has the MS on it, I was hoping to have her on the road already but had a problem with the way I had the return line from the regulator running back into the fuel line causing cavitation in the fuel pump. I am waiting for a new fuel tap from Jeff Saunders and I am machining up a fitting that will have the return line feeding directly back into the tank.
Ive had the bike from new in April 79, Ive changed a lot of stuff over the years.
I am tempted to try a manual tensioner on the bike as I have heard a few bad reports on the wedge type automatic one, whats you veiw on this?

If you are talking about vibration causing ridges on the ramp of the tensioner, thus causing the tension to not take up the slack, I have read the same
It's worth taking a look, and if that is the problem, then correcting it with a file should work.