Have been reading with interest F5's 4/12/12 post regarding EC300 lost power and rattle. Has made my head swim. I have what may or may not be similar problem, as follows.
At indiscriminate times my 2011 EC300 will go soft on power which is accompanied by a sound like the silencer has fallen off. Sounds real loud and raspy for a second or two. Power is noticably off for an instant but I can blip the throttle and everything returns to normal. Can not associate this occurance with engine being under load, or anything else for that matter. Happens a handful of times during course of a race. Again, the sound happens for a two count like pipe has come loose or something but quick return to normal.
I've done all the obvious stuff. Pipe and silencer mounts are tight, installed new exhaust o rings and springs, plug looks good, carb removed and cleaned, PV assembly cleaned, inspected and working like it should. This situation differs from F5's in that it's not characterized by a rattle as much as it is a brief sound like an open expansion chamber on a 1974 CZ. Something ain't right.
Theories?
At indiscriminate times my 2011 EC300 will go soft on power which is accompanied by a sound like the silencer has fallen off. Sounds real loud and raspy for a second or two. Power is noticably off for an instant but I can blip the throttle and everything returns to normal. Can not associate this occurance with engine being under load, or anything else for that matter. Happens a handful of times during course of a race. Again, the sound happens for a two count like pipe has come loose or something but quick return to normal.
I've done all the obvious stuff. Pipe and silencer mounts are tight, installed new exhaust o rings and springs, plug looks good, carb removed and cleaned, PV assembly cleaned, inspected and working like it should. This situation differs from F5's in that it's not characterized by a rattle as much as it is a brief sound like an open expansion chamber on a 1974 CZ. Something ain't right.
Theories?