Paul Maple

well, I replaced the cam shaft, rocker arms, adjusted valves. same thing. excessive fuel. I took apart the old carb and inspected it, it looks really clean and all jets were clean, float doesn't stick. I put the inline spark tester on, looks great, great spark, no breakdown. fuel pump arrived yesterday and I will hopefully install tonight. I holding out hope, but not sure. I really don't understand why out of no where I would have an issue with too much fuel on two different carbs????? hoping for the fuel pump, but not sure how a simple mechanical fuel pump would cause over fueling, would not the float stop this from happening? I have adjusted the eclip up (reduce fuel) still same issue..... ill post the results of the fuel pump upon replacement.... any other ideas....

thanks, I was dreaming about this ATV again today, and was debating and purchasing a fuel pump, yes I have one and per the Manuel there is a pressure regulator in the pump... for $11.00 worth replacing, gonna order now. thanks for the post.

ok, I purchase a inline spark tester and will see where that leads, I have talked to a Polaris Tech and he is thinking possibly the compression release mechanism on the Cam is failing??? I am not sure but have already purchased a new cam and rocker arms. this should be done this weekend and we will see. any more thoughts are greatly appreciated as I am kinda stumped on this one...………. no 100% sold on the cam issue as I do think it needs replaced but I think it should still be running.

Thanks for the feedback, yes wet plug as well as when cracking fuel will drip out of the exhaust, I have a Manuel and completed test for the electrical system and just to be on the safe side, I replaced the CDI, voltage regulator, stator, coil, plug and wire. this is my daily driver, I replaced the carb, I have adjusted the fuel air mixture screw 2 5/8 out as well as tried to lean it, I raised the eclip on the jet to the top position to try to lean out the fuel even more, I have tested the spark with the plug out, its good. ( or seems to be). if I go full throttle, it will run for a few seconds than shuts down, (too much fuel) pull the plug and its wet. I have left the cap off the fuel tank, fuel is clean. I agree on the valves and rockers, that is why I am posting it, there is excessive wear on the exhaust rocker arm and lobe for the cam, I can run my finger nail on it and there is a lip. I agree on the aftermarket carb as well, but this issue started with the original carb and due to the price I chose to purchase one instead of rebuilding, I have done this on some of my other ATV/Dirt Bikes and they have worked well. the one thing I haven't checked which im not sure on, I have confirmed the flywheel and cam timing marks line up, but am under the impression there is another key on the crankshaft and gear with the chain? I have not pulled the stator plate to verify this key is still good, but at TDC with the timing marks aligned, if I go slightly past the flywheel will automatically spin forward which indicates to me the piston is truly at TDC. any more help would be greatly appreciated as I am not sure that I believe the exhaust wear on the rocker and cam will correct my issue, though I do know they need replaced...

I have a 1999 Sportsman 500, it was running fine, than started to lose power in the winter, I adjusted the idle screw and away I went, than a few weeks ago it died, I have found that i am flooding the engine, compression was at 70PSI and due to the compression release mech. i assume i am good as it compared to the same PSI on a 2000 sportsman 500 i have. i cannot start the atv unless i go full throttle and it starts an runs for about 30 sec than dies, again it is flooded. i ordered a new carb off ebay as i could get one for around $40. put that in same issue, i have checked the timing, (good), valves out of adjustment i adjusted to .006 still same issue, i have found the exhaust lobe and rocker arm to have some wear, i have ordered new ones, but am looking for any other input in this area as well. would the exhaust cam and rocker arm cause the engine to flood? i have used a bore scope and the piston liner has good cross hatching still? any input would be great.