i have a 2004 Polaris sportsman 700 twin carbureted. I have an issue with the engine bogging down typically at about 1/3 throttle and up. It runs ok until I reach about 25-30 mph then it starts to run really rough and choppy. It will also do that if I hit the throttle really hard at a lower speed. I’ve been searching on forums for a while to try to find a similar problem and solution but have found none. I live in central California so no extreme temperatures, I service the quad regularly, have rebuilt the carb a couple times, put clean gas in it. I just don’t know what to do please help.

 

Hopefully it's the later build with the Kokusan ignition that replaced the crappy Ducati system. You can tell by pulling the front rack,popping the front panel and checking if you have the combo cdi/coil(Ducati) or the separate cdi and ignition coil(Kokusan) Also check the intake manifold especially under the carb clamp. This was a bad area on splitting,sucking air and hard to see unless you removed the clamp. You "rebuilt" the carb several times or just cleaned it several times ? If you did,here's the best kit for the 700.https://www.ebay.com/itm/2002-2006-P...ZZtY1E&vxp=mtr

 

 

You do have the later Kokusan ignition.Possible it could be the limiter fault,but it's built into the spedo,but I'd check out the belt and clutches first. With it revving up fine in neutral(with no load on it) but limiting under a load,still sound like it could be in the clutches or belt. There is an over ride bypass that some have done for the limiter,but I'd leave that until last until you eliminate it being clutch related.Go through the cheap manual on the clutch system first.Again it could be a slipping belt or worn ramp rollers in the driven clutch causing problems.Plus there is a good section on the spedo pin test.2004 Polaris Sportsman 700 Service Manual PDF Download

 

 

REPLACE the split intake manifold.. Vibrating around as it's running just sucks in air. This was a common problem on the 700. Oem is a high dollar part,but aftermarket manifolds are just 18 bucks.https://www.ebay.com/itm/CARBURETOR-...dW4J0N&vxp=mtr

 

 

Glad to hear it's running better. Another area was the split exhaust manifold allen head bolts that would work loose burn the exhaust gasket and leak. You usually can hear that. If it's leaking that can cause power loss and running issues. Some have posted about using an 800 exhaust manifold,but really not necessary imo. Just make sure the bols are tight. Remove and use loctite on them if they are loose and you might as well replace the gasket. Also check the exhaust donuts and springs. Replace if worn.