Oh? That's weird?

The .50 class fourstrokes are among my favourite engines for conversion. I consider them ideal, and I have four of them currently running, and 2 more on the shelf (all of them ASP by the way, but I see no reason why OS would not convert just as well).

What were your issues? My guess would be that heat insulation (decoupling) of the carb was insufficient, as that is the only reason I can think of.