Yamaha TRX850 Enthusiasts Forum

hi all,just adjusted valve clearance,and now have a large flat spot on small throttle opening around 2500 rpm....it idles fine and is good top end..but as soon as you back off it back fires..stop the bike and take off and is good for about half mile then plays up again..any help would be great.
ps. inlets had 0 clearance..and now the fault

are your exhaust headers seated properly?
Leaks at the flange where the pipes meet the head can cause backfires on over-run

Sounds like it could be valves, are you sure you set the clearances right? I always use the maxim it was OK - now it's not - what has changed?

It was OK before you set the clearances?