i emptied gas tank and filled with fresh fuel, installed new seals and float needle, new battery, new stator and pulse coil because one day stalled out and didnt start. i believe the only problem was pulse coil. just got it together last night and started right up. only now it sputters at half to wot thottle didnt do this before. seems to be a rev limiter problem(electrical). opt told me to pull black wire from rev but the problem still remains.
I was wondering if anyone had this issue before and what a fix might be.
1998 sportsman 500
thanks

 

You changed the fuel filter and the spark plug?
How dirty is you air filter?
Does it smoke black when it starts missing. Does pulling the choke out above 1/2 throttle make it better or worse?

 

yes forgot, i installed new spark plug too. not new fuel filter. havent pulled choke. didnt see black smoke, was dark out but i dont think theres smoke.

 

i thought its strsnge that seems run fine up to half throttle.
can cdi gone bad? or perhaps a not grounding issue?
i will try opening airbox and
/or choking at half throttle. fuel seems to run passed fuel filter ok.

 

ok, i took off airbox cover and still sputtered but was bogging too. opened choke sputtering same. dont really see black smoke but exhaust smells carbony. any other suggestions? i have one extra cdi would it be good idea to swap?
thanks

 

Only if it's the exact cdi for your model! Have you ever checked the valve clearance ,plus have you checked if the exhaust cam lobe shows signs of wear? Plus when you replaced the needle and seat did you replace the float arm and float needle(problem could be there if float arm is wobbly and worn, allowing to much fuel),was the float arm parallel with the carb body when you held the carb upside down? OPT

 

the problem in first place was the pulse coil. i just started changing stuff at first. the atv ran great until it just didnt start. the carb is fine i took my time and did it surgically and i took 13 mm measurement for float as manual said. as far as valves and exhaust they are fine. it really seems something electrical. i have an extra cdi thats only reason i was gonna swap that just to see. can a rectifier or regulator have anything with sputtering at half ti wot?

 

Regulator/rectifier shouldn't have any effect on the ignition,but make sure it's at least charging 14 volts at the battery at or above idle. The older machines were magneto triggered ignitions and could recoil start on a practically dead battery versus the newer model atvs. OPT

 

i will check the charge tonight. in manual it gives a good range of air gap for pulse coil and i went in the middle of that range. if the gap was too big or small that wouldnt have anything to do with sputter, right?
i will also check gap on spark plug but i did gap it according to manual specs.
i assume pulling the black wire alone off the rev limiter takes that whole part out of the picture?

 

People make a big issue on the air gap of the pulser coil,but actually there is very little room to adjust this other than a slight tap towards the flywheel! The pulser holder bracket is not slotted,but you can move the pulser a fractional bit before you tighten the two screws! Yes,pulling the black wire from the reverse limiter module eliminates this module and you would then have full power in reverse without having to push the over ride button,plus modules can short out and limit in forward also and I've seen some that would just die when you placed the gearshift in reverse because of a faulty limiter! The plug gap should be between .028-.032. OPT