Valve Shim

[mfhmme75]

I have recently took my bike in for maintenance and found that i may have a missing valve shim which is causing some weird engine noise, what i wanted to ask is what are the consequences of this ? will it affect my bike's performance and will it ruin it other than the annoying sound ? regards..

 

[Gelvatron]

Well shims are needed to make the valve train move so I'd say its very crucial, but if one was missing you would have very loud tapping noises , possible backfire loss of power or stumbling on acceleration, basically it's not a decal it's an engine component it was engineered to do one job,

 

[dpaul007]

How on earth does a shim go missing?? Weird. I'd get it replaced ASAP. As Gelvatron said, it's a crucial piece that sits between the cam lobe and the valve.

Also I'd be looking in to it myself, if you are comfortable with it. If the shop wants to dig in your engine on a hunch that it may be a shim missing, you are going to have a decent sized bill on your hands.

 

[mfhmme75]

Well I think it's dysfunctional or corroded rather than missing, should i post up a video/audio file of how my engine sounds like at the moment ?

 

[airoh69]

Well I think it's dysfunctional or corroded rather than missing, should i post up a video/audio file of how my engine sounds like at the moment ?

I think that would be the best. Just for you to know on my friends skyline R34 new engine we had a miscalculation of around 0,01 mm (yes that's millimeters) and the engine has a very distinct knocking and need to replace some shims. So imagine how sensitive that part is.