Low RPM/Low speed sputter on Pro-RMK

[BigBlueEdge]

Took my new Pro-RMK out for a first ride last night since we got another 4-5" of fresh on top of the good base we're developing. I needed to get some break-in time on it before our trip west in two weeks.

I noticed that at low speeds and low RPM (5500-5800) there is a tendency for the engine to sputter every so often. I'd hesitate to call it cutting out, just more like missing a beat from time to time. It seems to be fairly consistent in those conditions. Brrrrrmmmmm-bah-brrrrrrrmmmmm-bah-brrrrrrrmmmm...

I'm obviously running with the break-in oil in the tank and the ethanol resistor, not to mention 6-8K clutching while in MN at ~1000 feet, but this doesn't seem like it is attributable to any of those things. Anyone else have this? Is this just how the 800 behaves? Or do I have a problem I need my dealer to look at?

I also noticed that the low oil light came on even though the tank has oil about 1" above the low line. Is there a way to adjust the sensor?

Thanks,
Rob

 

[Arcteryx]

think so

Ya, I have notice a little stutter from time to time. Not enough to affect the performance of the sled but enough to draw my attention. I have noticed it on 2 different Pro's.
Not sure what it is.

 

[5.5switchback]

The sled will sputter on the first tank of gas. The extra break-in oil in the first tank of gas helps to protect the engine incase there are any air bubbles in the oil injection lines. The sled is trying to burn a gasil mix of about 15:1 much richer than the 50:1. It will come out of it on the second tank.

 

[BigBlueEdge]

The sled will sputter on the first tank of gas. The extra break-in oil in the first tank of gas helps to protect the engine incase there are any air bubbles in the oil injection lines. The sled is trying to burn a gasil mix of about 15:1 much richer than the 50:1. It will come out of it on the second tank.

OK, nice to know. It's been 9 years since my last new sled so I'm a bit out of tune at breaking in one.

Thanks,
Rob

 

[Old Scud-doo]

If it is under accelleration, I am not sure what it is. If it's under decelleration whether it be full release of throttle or lightly releasing the throttle, have th kill switch and harness checked. I had to have mine replaced and it is a known problem. Should be a TSB for the dealer.

 

[BigBlueEdge]

It's not happening under acceleration. It happens at steady throttle, very lightly applied. Just enough to keep it moving ahead 10-20mph on the flats. It idles just fine with throttle closed and it runs smooth decelerating.

For all I know, it could just be a characteristic of this engine.

Rob

 

[stormxz2]

Lean mixture?

 

[Old Scud-doo]

It's not happening under acceleration. It happens at steady throttle, very lightly applied. Just enough to keep it moving ahead 10-20mph on the flats. It idles just fine with throttle closed and it runs smooth decelerating.

For all I know, it could just be a characteristic of this engine.

Rob

That's how mine started out. It was just off of idle to begin with. It grew to where if you were going down the trail and started to lightly release the throttle, the sled would act up. Only clean up when running under constant applied power or acceleration. I would have your dealer check out the TSB for that kill switch and harness. If you have what I had, it is frustrating as hell to ride with.

It's in the little pieces throttle positions sensors and the switch. Under releasing throttle or low throttle the reading to the computer is getting screwed up by the sensor in that harness that tell where the throttle lever is positioned.

 

[wyodragon]

rough at low rpm

Mine runs rough at low rpm too. I only have 108 miles on it so I am hoping it gets better,it is on its second tank of gas and I have 91 oct in it and I have taken the ethanol plug out. My oil light came on for no reason also and the dealer replaced the oil send indicator. The low rpm running is annoying if you are trying to pick your way thru some trees,its like trying to ride a horse that only wants to run all the time,I like to slow down once in a while!

 

[Norway]

Mine does this to, only I saw 5300 as the "magic spot". If I cept it around 5300 it would burble and stutter but once I pulled the trigger or just blipped a bit higher it went away.

Just 2 hours on the first tank yet.

RS

 

[AndrettiDog]

I'm guessing a rich mixture. Check your plugs. Don't be shy to put a tank of 30:1 oil for breakin. You will run rich, but your sled will like it in the long run. Keep in mind the sled will run more lean at a lower elevation as controlled by the ECM.

I'm not sure how you can expect to determine how the sled runs with the weights way off.

 

[AKSNOWRIDER]

Took my new Pro-RMK out for a first ride last night since we got another 4-5" of fresh on top of the good base we're developing. I needed to get some break-in time on it before our trip west in two weeks.

I noticed that at low speeds and low RPM (5500-5800) there is a tendency for the engine to sputter every so often. I'd hesitate to call it cutting out, just more like missing a beat from time to time. It seems to be fairly consistent in those conditions. Brrrrrmmmmm-bah-brrrrrrrmmmmm-bah-brrrrrrrmmmm...

I'm obviously running with the break-in oil in the tank and the ethanol resistor, not to mention 6-8K clutching while in MN at ~1000 feet, but this doesn't seem like it is attributable to any of those things. Anyone else have this? Is this just how the 800 behaves? Or do I have a problem I need my dealer to look at?

I also noticed that the low oil light came on even though the tank has oil about 1" above the low line. Is there a way to adjust the sensor?

Thanks,
Rob

try putting the right clutching in for sea level, with that light of weight in it its running way more rpm at part throttle then it would with the right weights..throwing off the computer as to what it should be seeing..as far as throttle position vrs rpm...

 

[Old Scud-doo]

Took my new Pro-RMK out for a first ride last night since we got another 4-5" of fresh on top of the good base we're developing. I needed to get some break-in time on it before our trip west in two weeks.

I noticed that at low speeds and low RPM (5500-5800) there is a tendency for the engine to sputter every so often. I'd hesitate to call it cutting out, just more like missing a beat from time to time. It seems to be fairly consistent in those conditions. Brrrrrmmmmm-bah-brrrrrrrmmmmm-bah-brrrrrrrmmmm...

I'm obviously running with the break-in oil in the tank and the ethanol resistor, not to mention 6-8K clutching while in MN at ~1000 feet, but this doesn't seem like it is attributable to any of those things. Anyone else have this? Is this just how the 800 behaves? Or do I have a problem I need my dealer to look at?

I also noticed that the low oil light came on even though the tank has oil about 1" above the low line. Is there a way to adjust the sensor?

Thanks,
Rob

My sled is doing something similar and Polaris has not been able to fix it yet. It has nothing to do with elevation since I ride at 7500' to 8500'. My sled does it any speed and rpm as long as you are lightly backing off the throttle. So get cruising on the flats or down a slight incline and backoff the throttle just a hair to pull the load of acceleration off the motor and then it does it. Does it on the trail, in the trees, on the hill, does it everywhere I am and at any rpm. It's more of an "Unloading" the motor issue. As long as I am WOT or accelerating the sled is fine. Please post if you are still having problems. I am starting to think I am the only one according to Polaris. Thanks.

 

[Old Scud-doo]

SWEET!!! Dealer called and said they believe the problem I am having is an injector problem and two new injectors are being shipped today. Polaris supposedly has had a few bad injectors this year so far.

I sure hope this is the fix.

 

[sledfreek]

I have this same problem but didn't start til around. A hundred miles replaced plugs no good tightened throttle cable no help! One plug was really black other was the golden brown ya want! I feel it the most if ya pin just before the clutch engages and ya nail it but also when trying to side hill! Its never pops or makes a noise just like motor stops and comes right back! So annoying! Might be a little fuel still mixed in the tank but it should have done it initially more than 100 miles later! Mine is going into dealer so ill post my results to try to help!

 

[depthcharger]

I switched to the non ethanol plug and my hesitation/stutter disappeared. Im running non ethanol fuel also. Sled ran absolutley perfect today.

 

[1Mike900]

Read the RKTec reply on this symptom, seems to be the spark energy needs to be concentrated more @ .018 plug gap? See if this helps as these are lean burn engine. Mike

 

[BigBlueEdge]

I had mine to the dealer today. They noticed the issue that I described. But they didn't find any codes in the computer and since it is so new (25 miles) they suggested riding it for a while to get it broken in and get some non-mixed fuel going through it before declaring a disaster. I'll have to just have some faith, because I leave for the mountains in a few days and if there are going to be problems it will be a mess for me. Oh well, nothing else I can do.

Rob

 

[OnlyPolaris]

I would say ride the thing and see how it does in higher elevation and once it hits 3 hrs. A guy i ride with was having a similar issue. Once we hit high elevation and 3 hrs on the engine it went right away. so who knows if it is something to do with the lighter weights at lower elevations or the break in period.

 

[Clarke673]

my sled did this very slightly , but only for the first ride. After 300 miles with no issues what so ever, i think it was just because of the high oil mixture, the 91 octain fuel, and the 87 corn plug in. Simply couldnt burn all the fuel.