My brother has a 04.5 sportsman 500 - it will lose power at about 2500 RPM and slowly rev spits and sputters a little up to about 5000 RPM then it will die. It does idle and have plenty of power in the low rpm range. It will restart after a few minutes or a bunch of crankin once it dies. I have checked everything I could think of and cleaned the carb - it has about 250hrs on it. Any help would be greatly apreciated.

Thanks,

Rob

 

ANYONE???

 

Maybe check for spark when it dies. How does the plug look now??

 

the old plug looked ok but we did replace it, I had him adjust the ETC to no avail. I will have him check for saprk but it sounds like it is off to the dealer for diagnosis

 

Check to see if the air intake is not obstructed. Sometimes the sponge that separates the two snorkels gets stuck in the intake snorkel when putting the air box cover back on and will cause the symptoms you describe....

 

checked all vent tubes, air cleaner, fuel lines, electrical wires we could find and installed new plug - still no luck - any other ideas??

 

Will it run with the air box cover off??

 

Yes runs fine

 

Well like I said something is blocking the air flow into the air box choking it.....

 

Sorry, I mean it runs the same either way.