'08 700 RMK misfire, dropping cylinder, coils?

GMCRMK · Dec 21, 2009

So, first ride of the season doing a little hill climb and the engine stutters bad 3/4 of the way up. It then did it the rest of the day at varying throttle positions (WOT, on accel or even constant cruising).

It feels like it's dropping a cylinder for a second then picks back up. Also, it was hard to start intermit (5+ pulls) and on a couple occasions died at idle. It caused a few near stucks and some worry about being on the wrong end of a tow rope.

Our guess is that it’s loosing spark but both ignition coils OHM ok and cost $90 each so I’m reluctant to throw them on.

I did a search and found others had TPS, ECU & voltage issues but nothing about a cylinder type misfire which is what I perceive this to be. Any other ideas or things to check before heading to the parts house? Any one else have a bum coil?

Thanks.

P.S. Stock motor, 2500 miles, exhaust valves cleaned, new gas, plugs replaced, MFD displays normal, no engine lights, does not die when put in reverse (usually).

sledneck_03 · Dec 21, 2009

i see that you cleaned your exhaust valaves but did you check the belows? or when did you clean the ves? could have blown one since then....what happened to my sled replaced the fuel pump and checked a bunch of **** and then it was the below............

it would run ok and such but give it throttle and it was stuttery like you said

GMCRMK · Dec 21, 2009

^^ Just cleaned before the season started. Bellows are good. It was definetely a misfire...plus no start and die at idle intermit.

I keep thinking it's a coil(s) but looking for opinions. Thanks

FLYIN H · Dec 21, 2009

Been there and lived it. Just before I lost the exhaust side cylinder, piston and lower crank case... I believe mine was from snow ingestion after riding in 5ft of pow all day, sucking in through the light adjustment hole. Temp dropped to -25 that nite and I didn't get it inside to thaw out. I think it cold seized on the trailer when I tried to start it the next day. It would take about 5 to 8 pulls to start, always started on the 2nd pull before. 10 days later, boom! Hope it don't happen to you.

Kraven · Dec 22, 2009

I'd suggest the following

1) removing the fuel filter and see if you can blow through it.

2) Check fuel pressure, put an old oil pressure gauge onto the schraeder valve, mid 50 p.s.i. is where you want to be, if possible mount the gaugetemporarily, duct tape it to the handle bars if need be to where you can monitor the fuel pressure as you drive, PRESSURE SHOULD REMAIN CONSTANT AT ALL TIMES, IDLE FULL THROTTLE, UP THE HILL, WHATEVER!

3) I saw where you said dash info is normal, how about voltmeter , bar gauge on the right side of the gauge, is it dropping, losing voltage, early signs of stator failure??

4) Spark plug caps

I doubt it's the coil, possible, last time I saw/had a coil go bad was on my 1993 Storm

Good Luck, post some feedback!

GMCRMK said:
So, first ride of the season doing a little hill climb and the engine stutters bad 3/4 of the way up. It then did it the rest of the day at varying throttle positions (WOT, on accel or even constant cruising).

It feels like it's dropping a cylinder for a second then picks back up. Also, it was hard to start intermit (5+ pulls) and on a couple occasions died at idle. It caused a few near stucks and some worry about being on the wrong end of a tow rope.

Our guess is that it’s loosing spark but both ignition coils OHM ok and cost $90 each so I’m reluctant to throw them on.

I did a search and found others had TPS, ECU & voltage issues but nothing about a cylinder type misfire which is what I perceive this to be. Any other ideas or things to check before heading to the parts house? Any one else have a bum coil?

Thanks.

P.S. Stock motor, 2500 miles, exhaust valves cleaned, new gas, plugs replaced, MFD displays normal, no engine lights, does not die when put in reverse (usually).

GMCRMK · Dec 22, 2009

Thanks for the ideas. Funny you mentioned your '93 Storm. That's the only sled I've replaced a coil on too.

PSI = 60
filter = good
plug caps = ok
I'll check for the battery display this weekend. It does have the hand warmer update done already.

I have a manual so with the help of GIBSONMAN we'll check the usual suspects and I'll report back.

adam5187 · Dec 22, 2009

Is it running okay when it is not warmed up? The only reason I ask, is that one of the coils could be getting out of range when it is getting warm. Also did you check the resistance on the fuel injectors? Should be 12 ohms, Just a suggestion, good luck, let us know what you find.

SmokeyBear · Dec 22, 2009

FLYIN H said:
Been there and lived it. Just before I lost the exhaust side cylinder, piston and lower crank case... I believe mine was from

FLYIN H said:
snow ingestion after riding in 5ft of pow all day, sucking in through the light adjustment hole. Temp dropped to -25 that nite and I didn't get it inside to thaw out. I think it cold seized on the trailer when I tried to start it the next day. It would take about 5 to 8 pulls to start, always started on the 2nd pull before. 10 days later, boom! Hope it don't happen to you.

Has everybody seen the cover for the adjuster on the '10 models? Part #5438301, MSRP $1.99. I just ordered up a bunch to give to customers.
Check it out.

GMCRMK · Dec 22, 2009

I wish I was in lots of pow but I wasn't. I've got everything sealed anyhow (headlight, adjuster knob, airbox, hood to cowl).

The adjuster knob needs to be covered and not just for snow injestion either. See pic of my SLP cover.

FLYIN H · Dec 23, 2009

Just heard back from the Polaris dealer about Jr.'s 09 600 rmk shift. Symptoms were, bad plug fouling, having to hold the throttle about half way and it would start on about the 6th pull. Piston skirt failure. A week left on the waranty!

FLYIN H · Dec 23, 2009

SmokeyBear said:
Has everybody seen the cover for the adjuster on the '10 models? Part #5438301, MSRP $1.99. I just ordered up a bunch to give to customers.
Check it out.

Eliminated all the skylites in the dash with a Timbersled cold air intake.

GMCRMK · Dec 26, 2009

**FIXED**

I think I had two problems and we found two thingss.

First: The missfire:

Although the plug caps were tight, one of the cap connectors was ovaled and probably not making good spark. Good call Kraven. Fixed this in the shop and it ran good until....

Second. The no start/stall:

Sitting on a hill it would not start. If I hit the elec plate clutch cover I could get it to start but if I gave it gas the gauges would blink, warning lights come on and it would stall. Pealed back the harness but found nothing.

Thought it was the ECU but then noticed a white wire with a brown stripe had the connector cover pulled back. I don’t know what this wire is for (unless it's the female for the ethanol plug) but it caused the sled to die when the end would touch the clutch cover.

See photo - sorry cell phone photo.

Fixed that it it ran 100% all day.

Although I now know how to check a lot of other stuff and even made a TPS tool, the moral of the story is check the simple stuff first!!!

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'08 700 RMK misfire, dropping cylinder, coils?

GMCRMK

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FLYIN H

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