cam timing troubles on a rebuild.

I'm finally getting close to finishing the motor on my rebuild. (Just one or two more trips to z1!) This is a kz1000a2 (1978).

The crank was supercranked by falicon(they also replaced one rod and some rusty bearings). I've installed new low comp pistons from APE (je pistons), a new cam chain, new cam guide parts (ape and liska) except for the top cam guide(its out of stock at z1).

My problem is when I install the cams according to the manual, it can't be right because a valve contacts a piston when turning by hand! I've followed the directions 3 times and get the same problem, but the piston that touches changes! i.e.: the first time it was #2, then #4 and the #3. I'm obviously doing something wrong or my collection of parts won't play together...:sick:

Today, I'm pulling the head off and looking around to see if something wasn't installed right. Without the cams installed it turns over easily by hand no binding at all.

If it helps, the cams are stock.

thanks...Sam

Samwell wrote:

My problem is when I install the cams according to the manual, it can't be right because a valve contacts a piston when turning by hand! I've followed the directions 3 times and get the same problem, but the piston that touches changes! i.e.: the first time it was #2, then #4 and the #3. I'm obviously doing something wrong or my collection of parts won't play together...:sick:

Today, I'm pulling the head off and looking around to see if something wasn't installed right. Without the cams installed it turns over easily by hand no binding at all.

If it helps, the cams are stock.

thanks...Sam

This is an easy one. Some of your cam chain components do not match. Crank pin (15 or 16), Cam sprockets (30 or 32), Cam Chain (short or long). This is the "only way" what you describe could happen.

modprod wrote:

Samwell wrote:

My problem is when I install the cams according to the manual, it can't be right because a valve contacts a piston when turning by hand! I've followed the directions 3 times and get the same problem, but the piston that touches changes! i.e.: the first time it was #2, then #4 and the #3. I'm obviously doing something wrong or my collection of parts won't play together...:sick:

Today, I'm pulling the head off and looking around to see if something wasn't installed right. Without the cams installed it turns over easily by hand no binding at all.

If it helps, the cams are stock.

thanks...Sam

This is an easy one. Some of your cam chain components do not match. Crank pin (15 or 16), Cam sprockets (30 or 32), Cam Chain (short or long). This is the "only way" what you describe could happen.

I wondered about this as a solution. I have 30 tooth cam gears(counted them last night), the cam chain is 122 teeth (order from z1e - new in the box). The only change could be if the crank work required changing the crank sprocket and they used a 16 tooth instead of a 15. Unfortuneately I didn't count the teeth (or at least I don't remember doing it) and this will require splitting the cases again.:sick:

sam

Sam, just a thought but couldn't you use something to mark one of the teeth on the crank (I'm thinking like maybe white-out) and just count the teeth while you rotate the crank? Has to be easier than splitting the cases.

The Gringo wrote:

Sam, just a thought but couldn't you use something to mark one of the teeth on the crank (I'm thinking like maybe white-out) and just count the teeth while you rotate the crank? Has to be easier than splitting the cases.

Good idea! I've just done it, now I've found out that I have a 16 tooth crank sprocket... This won't work with my 122 link cam chain and 30 tooth cam sprockets.
Thanks too, modprod for the info, now all i need is a longer cam chain and new gears...

Sam