I am a bit concerned about the valve inlet gap

[piper]

Well I done my first valve check it took me 2 days but I also took my time. I was surprised of some of the inlet gaps spaces between the cams and the shims .08mm and .09mm the manual say .11mm to .15mm. I checked them 3 times, same spacing each time so I did not change any shims. I have kept a record of what is there at the moment the bike is running fine. There was wear on the each sides of the cam lobes where they hit, at the contact point and the realise point they look like they are scraping on the shims edges. Last month I perched a reusable stainless steel oil filter and so on the first inception I notices stuck to the magnet some metal bust partials I was a bit concern at the time but now I know that the wear dust is from the cam lobes. This is something that I will be keeping my eye on. What is your opinion about the inlet shims gap as .08mm, .09mm and the .10mm they are all between .08mm and .11mm the exhaust are between .16mm and.19mm in spec the manual says. 16mm to .20mm I am a bit concerned about the inlet gap.

Thanks PIPER

Edited May 31, 2009 by piper
High light

[MiCarl]

Pictures aren't sharp enough to see if there is abnormal wear on the cams. The only thing you should really see is a different finish, the part of the cam that runs on the shim will look a little more polished than the heel.

 

The reason for the .11-.15 clearance is because they tighten up when the engine is hot. If a valve ends up not closing combustion gases leak by and will ruin the valve. (The exhaust side gets hotter so it needs more clearance).

 

I'd go one size thinner on all the intake shims.

[piper]

So it is ok to run .03 thinner one of the intake is at .08

Edited June 2, 2009 by piper
Under stand better

[mm482]

Yes, you need valve shims .03 mm to .04 thinner. A little loose is better than tight.

 

Earl:thumbsup2:

[MiCarl]

Shims come in 0.05 increments. So if you go one size thinner your .08 gap becomes .13 - within spec.

 

So, if that intake valve that has a clearance of .08 has a 270 shim you put in a 265 shim and the clearance will be .13.

 

When you go down one size on your .09mm clearances your new clearance will be .14mm, within spec.

 

If you list your valves, their clearance (they're all intake, right?) and the shim on each one I'll help you calculate which shims to put in.