I have a 05 sportsman 90 2 stroke that idles perfectly and starts very easy but when you try to rev it up it acts like it has a rev limiter set right above idle, when you rev it up it starts stuttering like it is hitting the rev limiter. the fuel filter has been changed and is full of gas, new spark plug gapped correctly and new spark plug wire boot. I am at a loss and any help would be greatly appreciated

 

Has the jumper on the cdi been removed that limits rpm?? Has it been sitting up a while?? if so possibly just needs carb jets cleaned. OPT

 

the jumper has been removed off the cdi years ago, the battery went bad adn it sat for about 3 weeks but it fired right up after I put a new battery in it and my son rode it and it ran fine, a couple days later it started this crap

 

I would still check/clean the carb first,then if it still does the same thing, could be dirt,trash in the stator area (common problem as the way the plastic cover is designed) I would remove the right side cover and clean around the flywheel and pickup coil,traps a lot of dirt/mud and can start limiting or can fail completely. Basically the main problem electrical wise that I encountered on the 50 and 90's,coils and cdi's were pretty reliable,at least the ones I worked on. Keep us posted. OPT

 

i have cleaned the carb and the flywheel and pickup coil and it made no difference still have the same problem

 

is there a way to check the cdi box and the voltage regulator myself? also, could the asm resistor cause this

 

If the carb is clean and still having problems with cutting out most likely its the stator. Don't have the resistance specs on the white and white/red wires (pulser coil) or the red and black(main charge coil, BUT through Polaris the stator comes as an assembly. There are people who have matched them up with EATON (who make these machines) and have gotten them for a lot less than OEM. I replaced A LOT of stators on the 50 and 90 machines! Unless you have a short, bad plug wire,etc, I've never had to replace a cdi or coil or resister!! JUST stators would either just cause em to run bad, OR no fire at all. I've had customers say the same thing: running good one minute,then started running bad the next. I think its mainly because of dirt and heat that burn the stators out. You can try to get the resistance specs from a dealer or maybe some of the members have a manual on the 90, BUT if all else is good,I would bet on the stator. Sorry I can't be more help,can't remember ALL specs for all machines,just what I encountered the most!! OPT

 

I am having this exact problem with an 01 scrambler, carb is clean, CDI is new. Stator is out of spec on the Ohm readings. I was thinking this would be the problem. I do have one ordered should be installed by Monday, will see what we get for the end result. I post the result. This thing will start and idle but will not rev. Observed the stator was reading
Black to
W/R = 350 ohms. Spec is 450
Blk/Y = 435 ohms. Spec is 800
Y/R - .5 ohms in spec
W= .6 ohms in spec
Ground = 0 ohms in spec

Hopefully the new stator will solve this problem. Will let you know. Thanks old polaris tech. I have found your post on this forum very helpful.

BTW I have the harness to the electric choke disconnected, I have verified that it is in the closed position. This should just have the effect of no choke and will eliminate the common problem on these things of the choke malfunction.

Will post the success of the new Stator here soon. (Sell the confidence)

Thanks

Young Polaris Novice

 

When you replace the stator and crank it,just block the air intake tube with your thumb. Works better this way on initial crank up than the electric choke (junk) or even the manual choke. Just make sure all jets and orifices are open along with the small opening in the carb bowl a lot of people overlook. Didn't have the resistance specs 2 years ago on the little ones,but have them now and stator main windings do show out of spec by your readings. Hope the stator solves the problem. Keep us updated.

 

I got an 05 90 Sportsman as well doing the same thing..sat up for about 3 yrs..put a new carb on it..new plug..nott o easy to crank but when it does have to run full choke and wont run barely above an idle..has 90 PSI compression as well...Spark on the plug is orange not blue..Could this be a weak stator or coil?