Originally Posted by
airraptor
qwk the Italy ST 45 have lower timing and make better power down lower where the china made ones have higher timing but worse port matching. The china ones perform better with the Jett muffler than the Italy ones in stock form.
And they're "supposed" to be made the exact same..
My last reply was in relation to the Picco .45 which is said to be a fairly fast engine. I'd certainly expect more than 14,900 from one using a nominal prop and muffler.
FWIW, my ST S45 ringed turns 14,700 on a 10x6, 5% nitro, stock silent muffler. GS45 ABC (Italy - stock carburetor) did 15,250 on same muffler, fuel, prop, and plug. This is a well used engine too. The trick to the .45/51s (at least stock) is to thin the spraybar like they did in the .90s (.45 up to .90 uses same carb but .90 has narrowed spraybar). This frees up a lot of breathing. Mod the timing and bore the crank and you have a killer sport engine. The ST crank leaves a LOT of room for improvement alone.