Gpz 750 Cylinder Head and Valves

Hey, Jay ! Long time, no see !

I used to throw a few posts to You on drag bike, back when I worked at the Crystal Cathedral.

Good to see you here, too ! What's new ? How's life at APE ?

I really don't think that it's going to matter that you took .004" off the tips. If you take that much off you've taken off the surface hardening but it shouldn't matter that much since it's a sub engine. I think you'll be able to get away with it without any problems. Now that being said. Were the valves themselves ground?? How much margin is left if they were??

a bit late into this, but

if your valves are sunk a bit into the the head, would take care to measure installed spring length and and adjust with shims back to measure. if the installed spring height is to big your spring preload will be lower and you'll have a higher risk of valves floating

The problem here is, asking questions too late after the fact. On engines with hydraulic lifters, this is never an issue. On ALL engines with shimmed lifters it is ALLAYS an issue. Who did the head did not know what they were doing, as mentioned before but much more politely.

All of the seats and valves were machined by a skilled motorcycle machinist. After measuring the installed height, it was clear to me, the I was going to run out of shim selections. Nothing available below 200.

I am being very deliberate, careful and cautious on how I go about re-assembling this engine. I've had this motor torn apart at least a dozen times over it's lifetime. This aint' my First Rodeo !

That being said, I will make certain that the split keepers will not interfere with the retainers. Again, my goal here was to machine just a small margin, to permit the shim selections to be above 200.

If I end up taking off too much, then it will be time to get replacement valves. No biggie. Better safe than sorry.

You know us old nostalgiac bikers !...it's almost like owning a boat... " Bust out another Thousand " !

gpzman2000 wrote:

All of the seats and valves were machined by a skilled motorcycle machinist. After measuring the installed height, it was clear to me, the I was going to run out of shim selections. Nothing available below 200.

I am being very deliberate, careful and cautious on how I go about re-assembling this engine. I've had this motor torn apart at least a dozen times over it's lifetime. This aint' my First Rodeo !

That being said, I will make certain that the split keepers will not interfere with the retainers. Again, my goal here was to machine just a small margin, to permit the shim selections to be above 200.

If I end up taking off too much, then it will be time to get replacement valves. No biggie. Better safe than sorry.

I wouldn't go this route but if you call Web Cams they probably have some 180 or 185 shims. They used to anyway...