Never tried to modify the stock muffler on a Pilot but FL670 modified one on a FL350 and said it made a improvement without adding too much noise, the 350 silencer is similar to the Pilot wonder if the same mod could be done to the Pilot?
What say you Fl670

Details please.
Nutten wrong with playing with the stock stuff but I would jump right to the FMF Q2 Quiet Silencer Mod myself, have you seen this yet?
http://www.pilotodyssey.com/fmf1.htmshoubadaba is right get it running first...
Have you removed the clean out cover on the stock muffler and run the
Engine to blow out all the crap that accumulates in the spark arrester ?