Originally Posted by
xxxntwv
There is no way it was too lean it temped at 200,the engine was predetonating.I've been racing nitro for 12 years and can tune an engine with the best of them.I'm just warning those that want to remove a head shim do so at your own risk.Mine already started pitting the piston and button from predetonation.
How many shims did your engine come with stock ? reason I ask is that we have removed shims from at least 40 of these JL engines and not a single one has detonated...the stock compression ratio is quite low with the standard shimming and there would be no harm whatsoever removing a shim...However that is if they all come with the exact same shimming....