I have a 2005 280, it has always seems to be a bit louder than other gassers and pops and burbles on pick up from low revs, it also pops alot on over run. I have recently repacked the exhaust and have played around a bit with the jetting, i am currently running 118 main 38 pilot clip 2nd from top and boyseen reeds. I have also cleaned up the earths and fitted a new plug cap and lead thinking it might be electrical but no change, just wondering if anyone has any idears.

Kehin? Get it adjusted checked by someone who knows what they are doing.

I know nothing about Betas exept they all seem a bit like that to me ..it's almost as if they are awash with unburnt fuel getting sucked in from both sides of the "flow" I also am aware that they are prone to flooding and carb overflowing etc. I guesse you should be investigating these areas. sorry not to be more positive but lets face two stroke trials bikes are like people they are all different.