Hi,
I have a 2003 Polaris sportsman 700 and recently had is repaired at a dealer for a problem with the fuel pump. Not long after I got it back I noticed that it would intermittently loose power or bog down while riding in high gear. When using low range the power is completely inconsistent. The engine speed will go up and then bog down and then up again while holding the throttle steady in low gear. I contacted the dealer who recommended changing the gas to premium which lead to only a small improvement.

So far I have completely cleaned and inspected the carburetor. The spark plugs are new and look perfect. I checked the fuel tank vent which is clear. I checked the return air line from the rocker cover to the air box, which is clear and has the filter installed correctly. I have even changed the oil. I am at a loss to what could cause this and appreciate any input.

 

did you check the float level sounds like it could be running out of gas float set to low

 

I did not specifically check the float level but last time I cleaned the carb the float level looked like it matched speck but I did not measure. I will try to check tomorrow and re post. Thanks.

 

Also check your carb boot, the one bolted to the head.

 

I forgot to mention that I did check the carb boot. I have had that tear twice one me. I actually solved that problem by adjusting and adding some more vibration isolators to the carb mount. It doesn't tear tear that boot anymore.

The float idea makes sense. Does anyone know how to adjust the float to allow more fuel if that is the case?

 

most likely just bend the float tab so the float sits hiher in the bowl. make sure the fuel tank or fuel filter is plugged as well.

 

theer is a recall on the vent tube from the valve cover to the air box, the filter gets moisture in it and freezes and cracks, the new style vent tube has no filter, my old 03-700 did the same thing, get the new tube and see if it fixes it,

 

Ok some new developments:

I did a fuel level test acording to the service manual and found the fuel level in the float bowel to be 4mm high. I checked the float level and found that it was about 1 mm too high from spec. Also the fuel switch is allowing fuel to flow when it is in the off position.

So I don't know whether to return the float setting to spec or to raise it further to give it the gas it seems to need. Does anyone know which is more likely to work?

 

So I finally decided to have a dealer look at the machine. The dealer informed me that these machines shipped with jetting that was too lean in order to meet emissions requirements. He told me that it causes performance problems and overheating. I can't believe that was their solution. So the carburetor was rebuilt with and upgraded jet kit and the fuel valve was replaced (apparently it has been broken for a long time). He also serviced a recall which replaces air return form the valve cover to the air box. This was apparently related and the combination of air filter and hose caused restriction.

I also had them replace the leaky plastic valve cover with an aluminum one and replace the ball joints. (It has over 2500 miles on it!)

I got it back it is a completely different machine. I think it can blow away my friends warrior now (On trails at least) and it no longer runs hot! If you have an 03 you should consider the jet kit up grade.