2007 500 HO EFI .I've had a few problems with this machine since buying new in 2007.After about about a year the pdm went bad.After the replacement I noticed the tachometer was reading erraticlly,but the machine ran the same as new.The tach would read say 2500 @ 50mph on flat paved road.Or it would fluctuate from 800 to 4200 with the throttle at a constant postion going 35mph.I figured as long as the machine got to point A from B I was ok.In about oct of 2008 I came to a stop at a gate and the machine died.I was able to make it to the barn but the machine would not ildle (600 - 800 rpm then die).At that time I did electrical testing per the shop manuel.I found the air box sensor did't measure in spec.I replaced that sensor.Since that I had the poor Idle a couple of times but the machine allways ran fine.Today however was a different story.After about ten miles out the motor began to stumble and miss at low rpms.The first gate I came to the motor died.The missfire and stumble got worse and I turned around and went home.After the machine cooled I started it and it would barley run.Also it stored a 41 code.
I've done site searches and adjusted cables ,ect.
I need to get this thing running right.
Any one got a place to start?? I could use some help.

 

First I would check map sensor grommet that it mounts in on top of throttle body for damage,can seep causing problems. Normal for it to move around a little! Also check for any cut/broken wires coming into sensor. Jiggle wires to see if runs different,more than likely this can be the problem. Harness kits available.

 

First I would check map sensor grommet that it mounts in on top of throttle body for damage,can seep causing problems. Normal for it to move around a little! Also check for any cut/broken wires coming into sensor. Jiggle wires to see if runs different,more than likely this can be the problem. Harness kits available.

 

I pushed around the harness and the map sensor before with no noticable change in rpm .Tonight though the motor won't even stay running.

 

Just a thought if throttle slack too much( over 1/8") will not idle and die also. Still harness wires are tricky,can run good,then studder,backfire,then quit entirely! Wires can be broken internally causing problems. Just a thought?

 

O.P.T.
thank you for the feed back!
I'll mess with the wire's some more.
Also what do you think about the tach reading erradic?

 

Possible short in sensor harness can cause erratic rpm change. This may or may not be the problem,but for me this has been a common problem! Sometimes have had it happen shortly after machine purchased or like yours, a little later on.

 

Ok I spent three hours looking over the wire harness ,peticularly at the connections out of the motor that would relate to the cps.(this sensor would give the ecu and speedo a voltage ... )I took the air box out and started the engine. The rpms read about 1250 to 3000 . Next with the engine running I moved the wire harness around .I got the engine to miss and almost die in certain postions of the bundle of wires AFTER THE CONNECTOR coming out of the motor above the recoil housing.(the machine was running like crap.)
Next I pulled all the wires out of the ribbed plastic wrap.(I don't what this stuff is called but the heat around this area made this stuff very hard and rigid.)The black and white wires were secured in the ribbed wrap between two tightly drawn cable ties...I cut these and exposed a wrap of electrical tape. I cut the tape and found that the black and white cable actually had a third wire not being used.The frayed ends of this wire pushed into the insulation of the adjacent wires causing a short to ground.I pulled back the insulation and folded over about a 1mm section of extra wire.I taped this with heavy electric tape.
I reasembled everthing and my machine was back running good .
Although the tachometer was still not reading right.At wot from say 30mph to 50 mph the tach would actually drop to say 800 rpm from 4000 rpm.
I'm not sure I've solved the problem competley.
Any way I'm surprised at the abrasion that that happens between any components that contact on these machines.
O.P.T thanks for your help...