Hi everyone,..
I'm a newcomer to forums and also to owning a Polaris atv., though have ridden them over the years and am looking forward to learning and possibly helping others in the future also.
I have a second hand 96 Polaris sportsman 500,.. I've had troubles previously with the air box with air flow into it,..it had 2 holes cut out on the cover and wouldn't go at all until we covered them over and sealed it shut and was running great,...until recently. (Are they designed to be vacuum sealed like that or do they need extra air flow to box)..?
The bike takes off great and gets to a certain rev and speed and will only stay at that speed,.. if I keep accelerating it bogs down. We've checked fuel lines, carbi and are at a loss to identify problem. Can anyone help..?

 

You might have to replace the old air box bottom if the bolts are broken and dont seal the top completely! It will run lean and bog if not sealed properly. You could try to update this old system(never did one my self though) hope this helps. Plus the replacement bottom box has a new part # which usually means an improvemt! CANT get your image so I'm flying blind! OPT

 

Hey thanks so much,
That's exactly what's happened,.. the bolts are broken away from the plastics, down to only 3 holding it now.
So ive ordered a new Box hoping it will fix the problem.
cheers your a champion,
thanks
okan.

 

they are designed to have a sealed air box for sure for best running results. thats why when most people take there covrs off and start them they nnever seem to idle/run right until the cover seals it back up. imo

 

could also be worn buttons in the secondary clutch

 

This and also could be a bad cam.Older Polaris 4strokes are very prone to loosing lobes

 

the secondary clutch,
good point kerrbirds, were looking into it. I'll let you know how we go. Thanks heaps.

 

It wasn't the cam,..it wasn't the air box either, even though its getting replaced asap.
It was the 3 Buttons,.. not on the clutch,..but rather the rear one that has a spring in it,..it was all jammed up,..took forever to get it free and cleaned it up and replaced buttons. $10 job, though months of "head twist".Thats why the belt was fraying cause the front was pushing in and out but not the rear, and the revs hitting the limiter.
Thanks alot You guys are brilliant,.. "couldn't have done it without the advice".
Ps: taking out to the mountains tomoro night for a ride cant wait,.. tested it,..The Monster screams, runs better than before.

 

I never changed the buttons before even on our 97 SP500 with 7500 miles that still runs like it did from new. I wonder if I should just change them anyways and beat the problem to the punch?

BTW if it was the Cam lobe problem the major symptom is backfiring through the carb but we have not ran into that one yet as well.

 

With 7500 miles bound to have some wear on em, usually they grind down on one side and if worn down enough can break off ramp button screws,ain't fun if they do that. I'd replace em. OPT