Originally posted by w8ye
Engines with mild timing are generally not very responsive to Tuned pipes/mufflers nor Nitro as compared with a engine with high timing.
I'm not in the technical stuff of the exact meaning of mild timing, but from what I can see is that the engine has a very high exhaust port wich cuases it to be open some 170degrees.
Have run the engine with the standard muffler and it performed very poor. After fitting a tuned pipe it gained almost 2500 rpm. I have exerienced this engine to be very responsive to a tuned pipe.