I went over the thought process we used to use at our field- in my trainer days, I started a 55ax with a 12x6 (I think) prop and it flew nice and everything. But when I went into aerobatics with that semi-symmetrical 64" trainer (yes, it was possible on that airplane), I broke the prop somehow and then was asked to put in a 11x8 by my mentor. Though we never used to use either synthetic or nitro in those days, we did not have any overheating problems with the engine. So may be you are right with the prop size issue

I went back to my mentor (he has since become a bit irregular due to health issues) and pestered him into giving me a 13x7 APC from his stockpile of modelling stuff. Actually, I was looking for a 13x8 but 13x7 is also good. All my props are MAS, I use them for their longetivity but APC was all he had in that size.

I am also hunting around for a tach and infrared gauge. I have obtained the latter, the tach is a problem- lets see. Saturday will be a problem as its a working weekend, may be I can coax my bosses to let me come in a bit late

I also obtained the alcohol, just a case of mixing now. I want to make this brew without nitro first. I can always add some nitro later (about 150ml for 3%) later but once added I cant take it out.

I also obtained a bottle of RTV Sealent- the same kind used on HVAC duct work to seal holes. Again, problem there is that to remove it has to be scored off with a blade which is really not desirable. Remember, the screw that has stripped is one of the two holding the carb in place. The other one is still intact and the carb o-ring is still good and the first one is still there too. I dont think there is an air leak, especially since the engine does cut-off when the carb baffle closes

I will work through the problem and revert

Ameyam