2011 Pro RMK 800 Top End Bogging

[IceCap]

I will check that ground location.... I don't believe it is a plug or plug wire issue.

It seems that a lot of us are experiencing this issue ONLY after the sled has done several longer hard pulls.... which leads me to think it has to do with build up of heat... not water temps (they barely go up) but rather pipe heat.

Either the fuel map can't compensate for the higher pipe heat or the pipe sensor is not working correctly.
I think Polaris is in denial on this issue.

 

[black swan]

x2 here also.........last weekend towing a dead sled...heavy load, high water temps, 55 deg at 10k...hotter sled got, eventally developed a bad throttle bog.

2hrs later, air temps dropped to 35deg, normal load, sled was cold-normal, ran like a champ.

http://www.snowestonline.com/forum/showthread.php?p=3036670#post3036670

 

[linden]

Hey everyone,

It really sucks to read about so many people having these similar problems. I started this thread in January 2012 and my Pro has never been close to running 100%.

After many phone calls to the dealer we finally narrowed it down to the TPS sensor (at least we think), and the ride before it was going in the crank bearing went and that was the end of the shortblock. Warranty covered it (thank god), and now I have a fully rebuilt engine and I am going to break it in and test it out this coming weekend. The TPS sensor was not replaced, but reset to the correct voltage and tested.

I was hoping that it would be as simple as replacing the TPS sensor, but we will see how it runs. The snow is deep so I will be able to test it under heavy load and running hot.

I will let you guys know how mine runs next weekend.

Too bad the 2008-2011 M8 motors don't drop right in eh?

 

[RHODESIE]

Went out for two days, Fri&Sat, with warm ambient temps (6-10C). New stator and not one hesitation. 110 miles in some wet heavy snow. Under hood temps were pretty high i'm guessing. I have to had break in the coils that only occured at higher under hood temps. Ran great for both days and not one hiccup. Finally!

 

[Peevo]

For me the bogging started when I ran out of fuel for the first time, make me believe it is fuel related. I also refueled with lower octane fuel.

 

[threeamigoes]

top end bogging

I had the exact same issue happen but i have HM Turbo's 25 hp mod kit installed , when they installed it they put a new set of rings in it and it looks like they broke a ring installing them . I had a complete failure ring chewed up cylinder . check your compression ????? Im hearing more stories the pro's will need new pistons every 1000 to 1700 miles .

 

[IceCap]

My dealer replaced the ECU and it did not cure my top end bog. Mine only does it after considerable time at WOT. Like 20 seconds plus.
Now I am done for the season .... dealer will continue to try to resolve this issue next season.
If it is what I am thinking.... too much heat in the pipe.... I would like to hear from guys that are running the SLP pipe setup ... to see if any of you guys are experiencing this WOT bog??

 

[Murph]

Things to check since problem shows up after 20 seconds of WOT....

Pipe temp sensor
Fuel filter not flowing enough fuel for prolonged WOT
Fuel pump not flowing enough fuel for prolonged WOT
Injectors partially clogged
Also check ignition wires, if they are heating up might be arcing or grounding at wire to cap connection, or cap to plug connection

 

[linden]

I took mine out for 8 days of riding, broke it in and it ran well. This was with the brand new shortblock save the crank halves and head, the TPS was not replaced but reset and readjusted. Finally! No serious bog after 10 seconds WOT! It still feels like it is tired though, it will pull 8000-8050 for a few seconds and then slowly drop down but I am not going to worry about it. It could be too heavy in the primary but I am running 62's at the recommended altitude.

If any of you are still having this WOT bog after 10 seconds, I would definitely look into getting your TPS readjusted.

Hope this helps.
Linden

 

[volcano buster]

I am running a 2010 660 CFI-4. It has the same symptoms. It usually acts up when breaking trail for a while or pulling some good hills. I was up at St. Helens a week ago and wanted to make some long pulls, but it would start to cut out. It sounds very similar with what everyone else is describing. I do have a full SLP pipe/can. I bring this up as a baffle has come loose in the can and needs replaced. I'm wondering now if the baffle is creating excess backpressure and building up heat in the pipe. With 4 injectors I had wondered if I was simply dropping one creating a loss of power situation. This could be the computer doing it and that is all I am focusing on. I may take up MountainHorses idea and send the injectors in this summer to get professionally cleaned and then get the SLP can replaced.

 

[chris79]

Did anyone get a definitive solution to the issues. Having similliar problems

 

[Sled Solutions]

Did anyone get a definitive solution to the issues. Having similliar problems

Oddly enough my problem was plugged transfer ports on the exhaust valves. Take the valves out if you haven't already and break them down completely and clean them. Check bellows for any holes and make sure the 4 holes are clear on the cylinder. It solved my problem no question.

 

[Igloo Man]

Seems suspicious it runs hard and falls off, being you were running fuel with ethanol, could have had some moisture in it (being ethanol absorbs it) and it could have been freezing somewhere like your fuel filter or throttle boddies thus plugging stuff up, seen this before on a vertical escape 800. I would be curious to see what it would do if you put it in a warm garage over night and drained the fuel and swapped with non ethanol. If your taking it to the dealer see if they can check the fuel pump, perferably under load if possible and see if it is dropping pressure as it gets warm. It has got to be either running out of fuel, air, or a component is shutting down once warm. I haven't looked at my fuel filter, but if it's possible to install backwards it could cause this problem also. Then again the brake light coming on also points toward a possible electrical short, those can cause all kinds of problems. Check all your handwarmer/handlebar wiring out really good and make sure nothing is pinched or grounding out, stuff on and around the motor also obviously. Good luck and keep us posted.