i have a 2004 sportsman 500 h.o. i boggs like it is starving for gas when i was going up a hill. brought to a my dealer said it was a bad wire witch was a recall, now it's fixed..WRONG...NOW IT STARTS THE SAME THING OUT ON THE TRAIL. so i take it to another dealer.he says he rebuild the fuel pump it had dirt in it...he replaced the filter also.WRONG ..wrong still doing it.. so i take it over to my buddy an ASE master tech he put it on he machine (some kind of vac that run fuel threw the carb with out the fuel pump to clean everthing) still now boggs under load...hmmmm so he takes apart the carb cleans it out blows air thru it puts it back togather same thing....next step is some rebuild parts for the carb.....any body have a clue or has ever had the same problem
thanks

 

it could be that the float needs to be reset to allow more fuel in while going up a hill. imo

 

hi

I had the same problem, I dropped 8 main jet sizes. Totally new bike, 1000rpm more + 10 mph. Plug still blackish, still running plenty rich but works great now.

 

could be ignition breakdown might not be fuel problem at all.

 

Make sure and check the diaphram for the slide real close for small holes. Set the float to the .580 height. Make sure the plastic ring that holds the needle down is not crawling up the spring. It causes the needle to bouce. I have seen that more so on high mile units used for slow operations.

 

look really close at the float asm. had a few that the pins and holes on that plastic float asm. wear out of round and can cause problems.Compare it to a new one is best doesnt take much wear to cause problems.