my 02 sportsman run fine while idling and starts good, but when i get to about mid throttle it boggs down and when it gets to full throttle it starts to pop and surge. i already cleaned the carb (thinking that was the problem from dirty gas or something), reassembled and still the same thing. i even added a in line filter before the carb, just to make sure nothing was getting in the carb. i dont have the foggiest idea what's going on, please help!!!!!!!!!

 

Read the spark plug, it's easy and good information. Heck that might even be the problem. Doc

 

I had a 2000 scrambler and it did the same thing .the cam was wore out put new cam in worked great.might not be this but sure sounds like.

 

I assume you cleaned the main jet when you cleaned the carb

 

Its your plugs. starts fine but give it gas and chokes. thats a plug

 

It could also be a dirty air filter. I had an 04 sporty 700 that had the same symptoms when the air filter got dirty. Start and idle fine but then no mid and top range. When it was real dirty it would pop and sputter and drink gas like there was no tomorrow. I cleaned the carb out as well before I realized it was the air filter. Now I always try and check the easiest fix first.

 

if it runs pretty good up thru until 3/4 throttle then the main jet isnt causing it. it controlls from 1/4 throttle and up and would act up beofre that. what does the plug look like.

 

my buddy's expolere 400 did the same thing. turned out that the bottom drain bolt on the bottom of the carb had some small holes it. it would start and idle fine but once you gave it more than 1/4 throttle it would stall and die most of the time. make sure nothing is leaking at the carb. it was real hard to spot. cganged the bolt and now it runs great.

 

Could also be a pinched vent line or a cracked intake that these things are famous for.

 

changed the plug and it looked good, i think i'm going to try the new air filter suggestion. i tore the carb right down and there was a little bit of crud in the float bowl, but nothing major. it seems kind of funny to me that it would run great one minute then run crappy the next.