Originally Posted by
Charles Godwin
Measuring idle gap i honestly wouldn't get carried away with. Just set the idle like normal. If Person X sets it at, for example 1mm it could make your engine way out of tune as theirs might be richer or air temp cooler/hotter etc. I always stuck with the 2 shims that came with the engine as standard. I honestly didn't see any need to lower the head but it's worth a try i suppose.
Thanks. I agree that every engine is different due to tolerances which includes the head shims for example. It would be great if people would post their engine settings that would include Head shim thickness, HSN, LSN, Idle air gap, Fuel %, plug type. It would at least reduce the tuning variations and help noobs like me get a good tune sooner.
I was planning to raise the head slightly from 0.49 to 0.55mm. This would reduce the compression ratio slightly. The only issue I have is that my shim combinations are only 0.49 and 0.59 so I will have to see what I need to do to get the desired 0.55mm. I can always go back to 0.49mm if I reduce the thickness of my thickest shim.