Fred - even your pilot is smaller than stock - I don't understand.
I have a stock motor - RWR pipe, and K&N in airbox w/ no lid - 190 Dynojet main (185 mikuni), my plug is perfectly tan. If I was running your main, my exhaust temp would be through the roof.....no matter what altitude.


I've heard some mentions of motors running "okay" with too low octane - the effects of too low octane will not be heard or noticed most times - its the excessive wear and loss of long term life caused by excessive temp in the combustion chamber that high octane helps to reduce. Lean jetting causes the same excessive temp in combustion chamber. One should not be mistaken for the other.

 

I'm running a mikuni flat side. It is a HSR42 that is why there is a differance in the jetting circuit. much easer to start no vacumelag.