Disaster-->My cam-chain broke

If it's been a soft/rivet link type I've seen quite a few of those Hyvo's fail, even with good quality DID chain.
Either due to the link pins being riveted overly tight ( mostly from not using the correct tool) or failure of the links pins due to brittleness/faulty heat treatment.
It's false economy to fit a rivet link chain as they are notoriously difficult to rivet correctly and at the high mileages they do the rest of the motor usually needs a look at anyhow when it's time to change them.,

Hmmm... where did you get the cam chain? I have a brand new J cam chain waiting to go on a crank as soon as it gets back from Pearson. If there's a problem with aftermarket chains happening I certainly don't want to fall victim to it... PLEASE POST BACK ON THIS A.S.A.P

As a side note, I've used rivet type peanut chains before and never had a problem. I would not even consider using a rivet master link hyvo chain though, not in a million years

After looking closer at the cam chain and the top, I believe I have found the reason for the chain breaking. I don't believe that there is anything wrong with the quality of the chain, but simply that I've failed to tigthen it enough. I guess I needed to learn this the hard way :blush:

Here is a photo of the broken chain:

To me it seems that the chain has snagged on the inside of the head, i can see marks on the little knob on the inside towards the exhaust:

Also on the other side towards the carbs;

I can even see that there is another part on the chain where two links have broken:


As far as the damage goes, it seems to me that I've been lucky with only one bent exhaust valve. I almost cant believe it:


Is this likely to happen, that only one valve gets bent? I can't see any visual damage to any gears either, so I might have been lucky?

Next time after you have the cams in and the valve cover on put a 17mm wrench on and rock the crank back and forth while turning the adjuster in.

I would take a close look at that exhaust valve guide

Might want to check the valve guides too. At least the one with the bent valve. How bad is the piston?

tommyboah,

you can pour some gas into the intake then exhaust ports one side at a time and let it sit for 10 minutes.

If the gas leaks past the valve seat into the cylinder area ....... that valve needs to be looked at.

If you are holding gas for 10 minuets your ok,

Your very lucky that it happend on idle and not while riding. Would have been real bad.

Bad news guys, i looked closer at all the gears (I can't believe I missed it when pulling it apart). One tooth on the intake cam sprocket is busted, along with a tooth on the crank. F@%$! :pinch: Guess I was hoping too hard that things were ok?

Looks like the bike will be sitting for a while. I have a cam sprocket from my old KZ1000R2 cams that I can swap to the GPZ1100 cams that i was currently running, so I got that covered. The crank gear I guess is gonna be more of a problem. Does anyone know if this is easy to come by? Think I gotta hand this one over to the shop to fix...

All I can say guys, learn from my mistakes and don't do the same shit I did.

Basically need a crank or pay someone to take there's apart, ship it to you and get a shop to take your crank apart and press the new center in align it and check everything.

Poor elr

If you need a top of the line crank. I happen to have one.