shooting flames at mid revs

[jackbmx2010]

hey guys. my 70cc is playing up again. I snapped a rocker, replaced it and everything is back to normal but it wont run right. the first quarter of revs is ok and the last 2 quarters is perfect but the second quarter it splutters and sometimes shoots flames and takes a few seconds to get through it. The timing is 1 tooth advanced. Im running a 19mm carb on middle needle clip with about 1 1/2 turns out on the air screw. the weird thing is that it was all good before i had the rocker problems the rocker and nothing else has changed except the valve clearance on the exhaust which is now set at 0.05. Any ideas what could be wrong as im stumped ??

 

[sean01]

well for starters you valve clearance is way to tight... .001 thou spose to be .004..

advanced cam timing could be an issue.

but also look at the cdi and earth connections..

 

[jackbmx2010]

Cdi is all good cause I checked it on another bike. I meant .005 sorry to cause confusion but will try .004 and will check wiring and reset the timing. Thanks

 

[jackbmx2010]

put timing back one tooth and the bogging is 90% gone but i think its down to tuning. Thanks for the help