Originally posted by InitialD
Yes I have. 
Have you compared it using the JP crank with a normal piston sleeve?
Yes, but still on practice and have to wait for race meeting to get its optimum result and I'm afraid it will be pretty a while since I don't race too often
The torque almost comparable to my JP with harder clutch setting and leaner LSN (same carburetor) while top end is about the same. Fuel mileage still not sure...
What I'm curious the most is this BRB P/S comes with conrod and almost all of them has a very little bit of play in the crank pin even when they're brand new. Do you also have this problem?
I give my one and only .21 BRB P/S which I bought from kitracer (Thanks Chris
) to one of our best buggy driver here and he promise he will test it on his JP FX21 B5 and give me some result.