Bench setting of valves after rebuild 1982 GPZ750

Anybody know what the max acceptable amount would be? I figure I'd have to pull the head and measure everything to figure out the answer for myself.

These didn't come with Stellite tips or anything similarly fancy, did they?

Do you have a manual? It should be in there.
Steve

ayeckley wrote: Anybody know what the max acceptable amount would be? I figure I'd have to pull the head and measure everything to figure out the answer for myself.

These didn't come with Stellite tips or anything similarly fancy, did they?

Going by the book the max you can tip the stem is 0.30mm before you run close to the bucket riding on the retainers.
If you have access to a lathe and know what you are doing the collets and retainers can be modified to allow around 1mm to be removed.
After that you are looking at trying new valves to pull back the clearance and if that doesn't work then 1mm oversize valves will get back the clearance as the larger diameter valve head will sit on the unworn outer edge of the seat ( this is the main reason most older heads get bigger valves rather than for any performance advantage )

swest wrote: Do you have a manual? It should be in there.
Steve

That's just it - the Factory Service Manual for this model says that they should not be ground at all.

ayeckley wrote:

swest wrote: Do you have a manual? It should be in there.
Steve

That's just it - the Factory Service Manual for this model says that they should not be ground at all.

The FSM provides a CAUTION statement warning about possible contact between the split keepers and the bucket if grinding the valve, but in reality there is plenty of clearance to tip them a little bit. Keep the cutting down to .3mm as mentioned and you will be fine. Go for .2mm if you are worried. That's four shim sizes which will give your engine more life before you get into the really small shims sizes.

BTW, all the valves on my recently rebuilt 750E engine were tipped and there is plenty of stem sticking up above the keepers so no worry.

Oh, and on further reflection I believe the reason my bench check on the needed shims was too thin is because I checked the valves with the cam resting on the head. If you do this then I'd bump your shim sizes one shim larger since the cam will be floating somewhere above this point when the adjacent springs are pushing up on the cam.