I have a 2006 Sportsman 500EFI. this quad has been sitting for over a year or so, it would not start. I found a defective fuel pump. I have replaced the fuel pump the screen and the fuel filter. also the spark plug , air filter, crankcase filter. fluids and so on. ( a good tune up)
The quad starts up great now and idles right at 1200 rpms. (which is good according to my book) I now have a constant fuel pressure right around 39-40 psi which is in tolerance for my machine. I have a good spark. breather is not clogged to throttle body.
MY PROBLEM is the quad will not go over 40 mph, when the RPM’S hit 6000 it starts to act like its misfiring and not getting any more power. I pulled the plug( new) and it was black, not wet with oil but defiantly rich I think. I have no codes, and i have checked all but the MAP and TPS sensors, but if something was wrong with those wouldn’t it not idle or run good. I just was looking for some guidance on what else to check for. I know the quad is stuck in 4wd, I believe the roller cage in the front diff is broke and jammed. i have not taken it apart yet cause I want the engine to run right first. would the quad being stuck in 4wd cause the engine not to rev as high maybe.?? or do these machines have a rev limiter? i was also thinking maybe a clogged injector, since it did have gas when i picked it up and the guy said he didn’t use any stabilizer. the resistance on the injector was 11.6 OHMS. tolerance is 12 +/- .4
the ECU has not been recalled on this unit. I have Checked with a local dealer.
Any advice or thoughts on what to look for would be greatly appreciated, thanks
