Greetings all!
I've been a lurker for some time now, but this is my 1st post here. I have a 1999 Sportsman 500 that I just can't get to run right. It will start and idle fine, but misses badly when you give it more than 1/4 throttle or so. I can ride it if I go real easy but it always stalls immediately when you pull up and stop, however it will always start right back up and idle nice immediately. Why does it stall in the first place??!! :hmmm: I know after reading extensively on these forums that the cam is probably the main suspect. It looks perfect..
Aftermarket parts are extremely cheap on eBay these days so I started throwing parts at it. So far, Ive replaced the stator, CDI box, ignition coil, fuel pump and carburetor. (twice on the carb. The Mikuni still runs better than the $35 replacements :grin)
I've played with tighter and looser valve lash. I've ran a bunch of 2 stroke oil through it in case a valve might be sticking. I've tried with and without the airbox and filter. I even removed the muffler - it does the same thing only louder.
I've unplugged the black wire from the CDI box and it makes no difference either.
It seems to have good compression. I took the head off and inspected the valves/bore. Everything looks fine. The cross hatches still show in the bore. Its sat quite a bit during its life. It doesn't smoke or use oil. It doesn't knock or sound bad when it's idling. Why would it stall, then start right back up and idle perfectly?? Why won't it rev up??
What am I missing here? HELP!!
I've been a lurker for some time now, but this is my 1st post here. I have a 1999 Sportsman 500 that I just can't get to run right. It will start and idle fine, but misses badly when you give it more than 1/4 throttle or so. I can ride it if I go real easy but it always stalls immediately when you pull up and stop, however it will always start right back up and idle nice immediately. Why does it stall in the first place??!! :hmmm: I know after reading extensively on these forums that the cam is probably the main suspect. It looks perfect..
Aftermarket parts are extremely cheap on eBay these days so I started throwing parts at it. So far, Ive replaced the stator, CDI box, ignition coil, fuel pump and carburetor. (twice on the carb. The Mikuni still runs better than the $35 replacements :grin)
I've played with tighter and looser valve lash. I've ran a bunch of 2 stroke oil through it in case a valve might be sticking. I've tried with and without the airbox and filter. I even removed the muffler - it does the same thing only louder.
I've unplugged the black wire from the CDI box and it makes no difference either.
It seems to have good compression. I took the head off and inspected the valves/bore. Everything looks fine. The cross hatches still show in the bore. Its sat quite a bit during its life. It doesn't smoke or use oil. It doesn't knock or sound bad when it's idling. Why would it stall, then start right back up and idle perfectly?? Why won't it rev up??
What am I missing here? HELP!!

