i have a 1996 polaris xpolrer 400 and recently went to a sandpit ans screwed around when i left the 4-wheeler had no power and was bogging out it could only go about 40 mph. if u have any ideas please help me.  

Did you ever figure out what the problem was? I am having the same issue. The motor feels like it wants to go but it will only do about 35, and it did 55 before i went in the mud. Let me know.  

could have burned the belt up, check it for wear on the sides.
inspect the clutch and pulley for black marks (signs of the belt burning)  

Are you referring to the belt on the left side of the motor, behing the plastic cover?  

yes, that is the drive belt.  

I have a 96 425 magnum. Same thing, no power beyond 30 mph. Once the machine is hot and I pin the throttle, it gets up to about 30 -35 mph and starts bogging, back-firing, and shutting down. I'm leaning towards an ignition coil break down and have one on order. A weak coil doesn't work well when hot or under extreme load so hopefully this is my solution and may be the rest of yours. I'll let you know how I make out.
In the mean time, if anyone else has had similar problems or any suggestions, any advice would be appreciated.  

possibly the stator as well, if the stator is weak then the charging system starves for voltage.
and it can bog on hard acceleration.

it could also be a weak coil.

does it bog when idling and accelerating hard?  

I have a 99 Polaris 400 Scrambler and encountered the same problem....playin in the sandbox and whammo it starts to run as if in reverse with the restricter engaged.I noticed at this time that when in reverse neutral or forward gears the orange indicator light was faintly on to indicate when you are in reverse.When I noticed that I decided to try it holding the override button in and the motor jumped to life like always.This only happened today and my first guess is the black box on the frame that the transmission linkage runs through which has wiring running into it.As soon as I find one and install it I will return and post my results.
To see if you are having the same prob,see if holding the override button clears it up.  

i nedd to know how to pull the stator so i can have it tested i cant seem to get the flywheel to com off anyone know how to pull it  

wolf1:
possibly the stator as well, if the stator is weak then the charging system starves for voltage.
and it can bog on hard acceleration.

it could also be a weak coil.

does it bog when idling and accelerating hard?

It idles fine for awhile and then will sometimes just die out. It does bog under hard acceleration.
You think it may be the stator then?  

you need a puller and lots of time.
polaris likes to locktite them on.

i have had some i had to lightly heat to weaken the glue.  

depends could be the carb as well. especially if it has the split float design.  ( one float could stick down while the other floats well.)

it sounds more like the carburetor is loading up.  

hey people ive tried everything that was said to do and still cannot budge the flywheel anybady gat any ideas on how to pull this thing its gettin on my nerves and im about to get after it with the smoke wrench  

what did you find?  

HELLO I HAVE A 400 TOO. I CAN JUST ABOUT GUARENTEE ITS YOUR AIR FILTER. I HAD THE SAME PROBLEM. IT PROBABLY WILL VISUALLY LOOK FINE, TAKE IT OUT AND DRIVE IT FOR A FEW MINUTES. IF IT WORKS REPLACE IT. DONT KEEP DRIVING WITH IT OUT. IT WILL RUN TOO LEAN AND BURN YOU PISTON UP. HOPE THAT HELPS