Hello all,

New to the forum you guys are great love the responses and the great infomation.
My wife has a 2006 Polaris Sportsman 500 EFI H.O. Little History: about a year ago it would stall after riding for an hour or so then it would start after it sat for a bit, dealer changed out the MAP sensor (so they say) but it continued to stall so I changed out the fuel pump with the Carter pump this was ll about a year ago, but now it is really hard to start, warm weather or cold doesn't matter, I was told it might be the fuel pressue regulator which I found on this forum where I could get a fuel pressure regulator so I ordered it installed it but it actually made it not run at all so I re-installed the old one. I crank the engine for probally a minute or so some times it will backfire (loud POP) through the exhaust then it smells a bit rich, then it will start runs a little sluggish at first then it smooths out then runs fine but I can't figure out why it is so hard to start. I checked the battery with my volt meter and it is reading at 12.3 volts but interestingly when I do the diag. test it only shows reading ~11.5 volts, the battery is the original so it may be close to the end of it's life. Could this cause the hard start? Also another thought could it be the ingnition timing or needs valves adjusted It has about 3500 miles on it so if anyone has had any experience with this same issue would love to hear from you
thanks so much
ddkenney
SLC, UT.

 

Welcome! First off check charging at the battery while idling. Should be between 13.5-14.5 volts. This could be part of the problem(charging problem or battery won't hold a charge),plus most of the backfiring I had was from map sensor or tps sensor wiring shorts,either external or internal breakage. Just follow the harness wires down and check for breaks or soft spots in the wires.Plus check the crank sensor harness as it is bad about rubbing around the starter area. Any of these wires that may be damaged can cause the back firing. Sensors themselves rarely fail,(outside of occasional crank sensor failures) just the wiring.Plus check the "sticky" post above this section on efi wiring problems. Applies to the 500 same as the 700 and 800 models. OPT

 

OPT Thanks so much I will check the harnesses.