I have this 500 that will not start anymore. I have gas in the bowl, spark at the plug, changed the oil, new float, needle, seat, and diaphragm. I have completely degreased and cleaned the carb, pulled all jets and removed all dirt build up. Made the correct adjustment to the air pilot jet. It turns over fine and if I hold my hand over the intake of the carb it will start and it if I keep it there it will continue to run. I have not checked the compression but I can feel it with my hand over the spark plug hole. I can't figure this out. Help please its been 2 months and no atv to ride.

 

Have you checked the fuel filter? Check for any cracks from the carb to the engine on that rubber boot, also from the airbox to the carb. Sounds like it is starving for gas if holding your hand infront of the carb helps it start, how about using the choke does that get it running for a bit? I had a 2001 magnum 500 and it was bullet proof, have you like yours, outside of this issue??

 

I love my magnum, I have a bucket and winch and used the crap out of it, the 500 has plenty of power compared to my ex 05 honda 400.
I have checked n cleaned the filter. I get good gas to the bowl, has a good vaccum on the pulse line. I didn't see any cracks in the carb and I didn't notice a problem with the boot but will need to check again. I know it has to be a vaccum leak some where but I just can' t find it. I was going to take it to a mechanic today, I have exhausted all I can think of.
thanks

 

Are you sure you got the pilot jet fully cleaned out, I have had issues with that before, takes alot of choke to get it started, then it wants to die without choke. I take mine out and let it sit in Coke or Pepsi for 1/2 hour and then use carb cleaner and compressed air on it. Or use a small wire and carb cleaner. Or buy a new jet. It is a very small orfice. Was your magnum 500 a silver one. That was a nice color!!

 

Actually that is one of the parts I replaced, I did pull all the jets out and used a degresser and them air to blow/dry. This carb looks brand new now. I am a mechanic at heart and never had this much trouble before it just irritates the heck out of me. I think I drop it off at the dealers tonight and see if he can find the trouble, I have put a lot of time into this and if can fix for $100 or so then great less stress and thing for me to deal with, I just want to go fishing now.
Thanks