Here goes. This sportsman runs great unless you load it up or open the throttle up into the higher rpms then its like it runs out of fuel put fuel pump on it check lines put all new parts in carb if i take the air filter off and block part of the hole off then the thing runs perfect. got me baffled

 

Sounds like its lean, you should be able to pull the choke out while its running and do the same as blocking off intake,did you check float level and clean all the jets out while you had carb apart? What new parts did you put in carb?You did'nt put a smaller main jet in it did you?

 

needle valve seat jets diaphram and spring it was doing the same thing before we ever worked on the carb. we checked the valves clearance today they were fine and yes if you open the choke it does run right. Just has us baffled to what else it could be

 

Put one size bigger main jet in it, did the bike come from a higher elevation? It would be jetted leaner if it was at higher elevation.

 

no it was bought new here in arkansas i thought about a bigger jet might work the local polaris dealer said they had some air problems with these sportsmans maybe old polaris tech will chime in.

 

Only sold a couple 335 Sportsmans, Shows to have a 150 main and 40 pilot. Is vacuum slide opening up all the way with your finger? Have had some springs jump around,limiting slide travel,Just a thought.

 

Is the airbox complete? Make sure the snorkal and the seals and the drain plug are all in factory. There was a bulliten out on the 99 models for the airbox snorkal getting pushed against the gas tank by the seat and make it run bad. This caused a rich condition but it ran just like you had the airbox lid off off.The fix was to cut about an inch off the snorkal to keep it off the gas tank. The carbs are vaccume driven(I know you know that) so the barametric preasure that the airbox creates is critical for the carb to create the vaccume for the fuel pump and to lift the diaphram in the carb. Make sure the foam that holds the snorkal for the airbox and belt air intake isn't getting sucked into the air intake. Hope this helps

 

ncrider that does make alot of sense i will check that today.

 

Ok just a little update ncrider was right the snorkel was sucking to the tank we cut it and now runs like a new one thanks.

 

Great, have fun riding!!