Valve Adjustment Tolerances - How Far Do You Go?

[Cormanus]

I just looked at your question again, Dave. Unlike others here, I'm not expert, but, as Dubs said, there are specs for a reason. If it's in spec — that is, within the tolerance — I'd leave it. If it wasn't, no matter by how much, I'd adjust it.

[dave]

Thank you for all the answers guys! That's the exact feedback that I was hoping for.

To reply to the question about why not adjust a valve if it was out of spec: It's a heck of a lot of work to adjust the valves on these bikes. After checking the clearances, I estimate it would take me probably an additional four hours to pull the cams, measure the existing shim, determine what replacement shim I needed, and then put everything back together, and this doesn't include the time to drive to the dealer to purchase the new shim. I am sure that Honda designed these engines with some factor of safety concerning the valve clearances, meaning these engines could probably run perfectly fine with the clearances at half of what the factory recommends without causing any issues. There are a lot of very skilled and experienced people who post to this forum who have a whole lot more experience than I do, and I was curious what their opinions were if I was to continue riding my bike with one, or more, of the valves just slightly (.001 inch) out of specification.

Again, thank you for your answers.

[GoldOxide_imp]

Indeed. There is enough labour involved just to check the clearances.

But, and as with anything in the material world, 'tis the price of piece-of-mind.

[Tev62]

Don't forget that minimum clearance is on a cold engine. That might be closer still on a hot engine depending on the design.

[The Gecko_imp]

Don't forget that minimum clearance is on a cold engine. That might be closer still on a hot engine depending on the design.

Very good point !