Could you gasser boys help please - my mates 99 321 sometimes backfires when restarting after walking a section -Always starts - same power -nothing been touched ingnition wise.A few weeks ago he left the petrol on for a couple of days and had trouble starting it,so now turns it off every night, my thoughts are - floats letting petrol through when stopped and backfiring because of fumes in exhaust? A carb clean is on the cards,any suggestions welcome Thanks

Hi Dale,

I always turn off the petrol tap when finished riding, petrol may enter the crankcase while the bike is sloshed around on the trailer/rack to and from trials.

Clean out the carb, won't do any harm. Make sure the emulsion tube (needle jet) is removed too. Pilot adjustment approx 3.5 turns out from fully in. Out to richen. Needle setting, 2nd clip off the bottom.

Give it a good blast when warm to burn any excess fuel in the system.

Bye, PeterB.

http://www.gasgas.com/Pages/Technical/backfire.html

Read that article. It helped me on my 2000 280.

--Biff