Valve clearance exceeding factory specs

kawasaki mike wrote: ...I am running an exhaust valve clearance of 7 thousanths and intake at 4 thousands across the board on a 77 kz 1000.Engine is stock except for a 1015 set of JE pistons at 10 1/2 to one comp. Will I be ok if I don't ever red line the motor. I usually just cruise and very seldom hammer it hard.

Factory specified clearance is .05mm ~.10mm for both intake and exhaust (.002"~.004").

I don't have hands-on experience with clearances exceeding .10mm (.004").
However, some knowledgeable owners are reporting success with up to .15mm (.006") clearances, especially for exhaust valves.

As to the exhaust clearance at hand, I don't know whether .007" might add to the risk when running over red line.

Am thinking valve float is a primary cause for damage at high rpm. And that heavier duty valve springs help reduce valve float.

With the higher clearances, the valves aren't opening quite as far, which might offer some minimal reduction in risk when running beyond red line.

Would hazard a guess that the .007" exhaust clearances at hand might increase tapping noise (compared to .002"~.004" clearance); but isn't otherwise particularly harmful, and doesn't increase the potential for damage when running over red line.

At next clearance adjustment, could consider using next size [strike]thinner[/strike] thicker shims for the exhaust valves, to reduce the existing .007" clearances to .005".

Good Fortune!

EDIT: As 893cv aptly noted, a thicker shim is needed to reduce valve clearance.

On the 750 twins, the factory manual spec was .002 - .004" but was later opened up to .002 - .006". I run mine .003 - .005". I don't know if .007" poses any risk, I doubt it if the design is bucket over shim. If the shim is on top, I guess there's a microscopic chance it might shift out if the clearance was too loose but it would have to be really loose.

Patton wrote:

kawasaki mike wrote: ...

At next clearance adjustment, could consider using next size thinner shims for the exhaust valves, to reduce the existing .007" clearances to .005".

Good Fortune!

You will need to use a thicker shim to reduce valve clearance.

893cv wrote:

Patton wrote:

kawasaki mike wrote: ...

At next clearance adjustment, could consider using next size thinner shims for the exhaust valves, to reduce the existing .007" clearances to .005".

Good Fortune!

You will need to use a thicker shim to reduce valve clearance.

Thanks, 893cv! You are absolutely correct!
Thicker shim to get thinner gap.

Good Fortune!

I like those because the camshaft doesn't need to come out. not that I have any experience with those, although the sho is running rough.