Fuel problem?

[AcidRich]

Hi,
My new TRX has a cough. Around 4000rpm when cruising there is a slight misfire. Really shows up when I throttle back from the same revs & then on again, slight pause/stutter & then off it goes again.

Bike has Scorpion cans, K&N & a dynojet cert etc. Tried the standard cans but made no difference.

Any help advice would be appreciated.

Cheers
Richard

[Smithers]

Yup, I have had the issue and tinkered with a few things to get it right, so I cannot tell you for sure which one did the trick for me..........at present that "lean" spot is either gone or barely noticeable....anyway, the two things that could have accounted for the improvement were; winding the idling mixture screws out to the standard three turns from stop, and also rotating the throttle position sensor around a little further from minimum indication on the rev counter (when it indicates 4000rpm).......at higher altitudes and at just under 4000rpm my bike would really misfire till being throttled to under or over that zone which leans me towards believing that this was a lean mixture issue......someone on this site also recommended to being sure that the vacuum slides were free and that they could be polished with a bit of fine emery if they were sticking in their guides ( I havent had cause to look at them yet)......to alter your throttle position sensor you should be able to grip the screws with a decent set of pliers to loosen them. I replaced mine with cap screws..... this is an issue that others have encountered and appears to be a matter of adjustment or making subtle changes, I think......good luck