My P650 has a strange condition.[img]i/expressions/face-icon-small-disgusted.gif[/img] It runs fine in the mid and beyond RPM range but at low RPM it spits & sputters and backfires. It will be idling smooth and then it will start missing again and after a couple of minutes will smooth out again and keep cycling back and forth. I've changed the plugs, adjusted the idle mixture screws, cleaned and adjusted the choke, and put fresh gas in it. It's not the belt switch since it runs fine once you get the revs up but that's what it acts like. I'm beginning to think it's an electrical problem. Could it be the low end module bad? Has anyone run in to this? Any suggestions are appreciated.[img]i/expressions/face-icon-small-confused.gif[/img]

 

Man - tough crowd. Nobody can offer anything at all?[img]i/expressions/face-icon-small-confused.gif[/img]

 

Where are your idle mix screws set ??? with the mods you have, I'm assuming that your jetting is correct ??? to me, it sound like you may need to adjust the screws in or out ( fine tune ), or perhaps you have a sticky needle valve, or need to put a spacer in or adjust that setting if the Dyno Jet needles where used... I had a problem where I lost all my power... turned out to be a small piece of plastic ( from the factory drilling during the gas tanks manufacture or installation ) cork screwed into one of my new jets... I had 1100 hard miles on it when the plastic piece appearently finally broke off, but only about 20 miles on the newly installed jets... I highly reccomend installing one of the see through inline gas filters... it does sound like it's fuel related to me, but my dealer was all set to test my coils, as they said it sounded like week coils to them ??? perhaps you have a wire going bad ??? car wires go bad all the time, but I rarely hear of anyone replacing wires on these quads??? Sorry I couldn't offer more insite, maybe someone else can offer some other suggestions...WAM

 

newbeatle - I do appreciate the response. The mods were done almost a year ago and the thing has always run like a scaulded dawg. It still does at mid to top end but has the miss at low revs. It was running rich at the same time it started missing. I changed the plugs and leaned it out. It is not running rich but still has the miss. I don't know what it is. I've played around with the fuel tank vent system and thought I found something there but it's still missing. I'm going to keep after it.[img]i/expressions/face-icon-small-disgusted.gif[/img]

 

as long as you keep the throttle hammered you wont have that problem[img]i/expressions/face-icon-small-happy.gif[/img]

 

had the same problem with mine and it took a bit of begging to get it fixed by the dealer
after they fixed it they would not even be specific on what they did
they used 4 3mm washers but im not sure where
and they said they richened it up
cant tell you much more

 

mine was doing the same thing and i went in and put spacers behind the needles. They helped mine do make sure that diaprhams are not suck.

 

How about your choke hanging up? Check to see if your plungers are going all the way back.

 

I am now having this problem with my 700 what is the fix. My bike runs rich at idle and is missing on the front cylinder. I have changed the plugs. I have changed the mains put spacers behind the needles and have taken them out. When you start it I have found that you need to push the gas a little. I never had to do this before. I also switched the slides from one carb to the other I also switched the coil packs. I have it running a little better but still misses at idle can anyone help.

 

CHOKE SPRINGS!!!! part # 92081-1720 need to order two of them.....