07 summit electrical problem....i think

[bingo1010]

my first post here so dont be to hard on me, i have searched for common problems but cant seem to find anything. i recently bought the wife an 07 800 summit, it has 1500km on it and runs good for the most part. the problem is when the thing is idling it almost seems like it is running one 1 cyl occaisionally,it doesnt idle smooth like it should, the airbox shakes and jumps bad. when you take off with it again it seems like it is not running smoothly, if i slowly bring the speed up to about 25-30 mph then it changes and starts to run great, almost like it is hitting a powerband like the old 2 stroke dirt bikes. more info, occaisionally when i start it the tach doesnt work, sometimes i have to rev it up enough to get the clutch to engage several times before the tach starts to work, when it is doing this it seems like the ignition timing is out, again not idling properly. more info, when i try to get it to go into reverse quite often it just dies. here is what i have done/tried so far, compression is equal on both sides at 130 psi, the machine has normal power once you get it past the 25-30 mph mark, so i dont think it is mechanical related. plugs have been changed, i swapped the coil and plug wires from another one of my machines with no change. i have turned the idle up to try to fix the reverse problem but that hasnt helped.i am pretty sure it is all related but not sure where to start.i thought about swapping the ecm from one of my other 07 machines to check that, but am not sure about compatibility.it acts like the timing/ignition curve is out at the lower rpm 's ? any ideas or thoughts?? i am quite sure it is an electrical issue just because i do have problems occaisionally with the tach when i start it. one last thing, when it is idling and warm if i flip the choke on the idle pulls down like it should but when i shut the choke off the idle picks up to the point that the clutch will engage and move the machine, i dont think this is normal, but i dont believe it is related to the other problems i have mentioned.

 

[Summiteer]

Bad Stator? Doesn't put out enough juice at idle to for the ignition? What voltage do you see at idle? Any difference if handwarmers are off and headlight unplugged?

 

[vjc]

Is the airbox wet on the inside? Left or right side? Cracked reed......

 

[bingo1010]

airbox is dry, havent checked voltage, but handwarmers and headlight all apear to be working fine, what is the easiest way to check the voltage?

 

[summitguy]

The bad engine shake could be primary clutch is not lined up ?? Buddy had same problem

 

[bingo1010]

i have taken the primary apart for cleaning and all the marks line up, i am thinking the possibilities are,,, as mentioned the stator, or mpem, or bad elec connection, what about the tps??? is there any way to test the tps without taking it to the dealer?

 

[Murminator]

R motor or HO?....sounds like she sucking air carb boot or crank seal....is it hard starting? flooding?

 

[vjc]

It's sure sounds like some sort of a air/fuel problem
I still think it's a reed problem, stumbles at idle, cleans up at higher rpms.....

 

[bingo1010]

It is an "r" engine, I will pull the carbs and reeds off today and check it all over good, it starts good when it is cold or hot, thanks for the ideas so far, maybe the tach thing is a separate thing , I am going to pull the mpem connection today and clean it up good also, thanks for the ideas

 

[Lightningmike]

Mine was poor idle and stalling going into reverse as well and it was a plugged pilot jet on one side. Ended up having bigger issues than that but they said that s what caused idle and reverse problem.

 

[bingo1010]

update,.... i fired up the sled with and started spraying eether around to see if i was sucking air anywhere, sure enough, the engine sped up when i sprayed aroung the pto side seal. so i pulled the clutch, popped the cover off to replace the seal, noticed there wasnt a lot of grease in the bearings so i filled them up. put the new seal in. just for the hell of it i thought i shoud check the crank runout.....got .006". i know the spec max is .0024". with this in mind i know the engine needs to come apart to get a new crank, i will have the cases line bored at the same time also, next.... do i dare drive this thing at all with this much runout ?

 

[Murminator]

Depends what your using it for to finish the season with ....going to the hills and doing 8000RPM pulls chances are you with chasing a clutch down the hill after is spits out through the belly pan. Or if you are doing so trail and flat land riding she will probably hold up good....but I'm no mechanic