I have a 1999 Sportsman 500 that is giving us fits. It started to lose power on hot days this spring. Will start & run but has no power and might go 30mph. We adjusted the clip in the carb a couple of clicks to get it more fuel and seemed to help until the summer hot weather came. So we adjusted the clip to the last spot the other day and seemed to run great for a few days of 90+degree weather.

Then we used it yesterday for a football camp hauling water around to players all day and by late in the afternoon it acted up again, worse then before.

We have checked the valves and it has good compression. We also sprayed ether around the carb to see if there were any seal problems. We are totally baffled at this point.

Any suggestions are appreciated as my mechanic is confused and I'm barely mechanical enough to change the oil in my mowers!

Thanks!

 

not sure in what yrs. but they had cam problems in the late 90's where the lobs off. may be a cam problem where its loosing power. just a thought for ya.

 

Actually had the pleasure of replacing that a couple of years ago[img]i/expressions/face-icon-small-happy.gif[/img]
Thanks though.

 

you said you adjusted the valves as it would loose power if they were to tight when they get hot so you ruled that out. what about vent lines to the carb and the gas tank. there all clear and not pinched cutting off breathabilty? thats all i can think of.

 

I would disassemble carb and clean jets. Make sure you dont have old fuel in tank.

 

Vent lines are ok and just filled her up yesterday

Thanks

 

Is there any way this could be electrical at all? Like I said, I'm not very bright about this stuff but I'm reaching at straws here.

 

Check the secondary clutch ramp buttons.

 

is there oil in the air filter box? if so, might be just worn out rings. How many hours or miles are on the machine?