Oh, no offence taken...

The pattern guys in the club use 25% nitro in their YS's...every one else uses 15% club fuel...
I've seen more props thrown with the YS's than with the other engines...and the sandpaper bit works well...
Most have to replace the rod every season because of wear on the bushings...Mo' bang in the fuel...
Some other motors are just plain 'finikie' with the needle settings.

Hope this helps some...