Originally Posted by Solara

I have a brand new Nova Rossi Bonito .21 engine for my GT. I am like 4 years away from racing NITRO and I am sure I am way off about tunning or setting for nitro, but I want to know...if I am running Byron 25% thru out, do I have to remove ADD any head shim just to not blowing glow plugs on every round..?

I know back then...when running 30% fuel, head shim need to be added in order to not giving too much compression when running 30%. But for the Bonito, will the stock head shim thinkness is OK for 25%? From their diagram, it listed there are two 0.3mm and one 0.2mm that is = total 0.8mm. I have no problem to add 0.1mm more on the head as I DO NOT need the motor to run the absolutely fastest. I want my glow plug to last and not having the engine shut off on a one hour race...

I will just follow the manual said and run in the engine for 30 minutes and then lean the crap out of it...LOL