2012 Polaris RMK's Running Hot?

[rockinmranch]

2012's are hotter

I have both the 2011 and 2012 Pro 800's with 155 tracks, set up exactly the same. Even after 150 miles on the 2012, riding side by side, same conditions, scratchers down, switching riders, the temps on the 2012 is significantly higher unless in 6" or more of fresh and going at least 20mph - then they both run close - the 2011 123* constantly and the 2012 125* constantly. The highest that the 2011 got was 138* on hardpack while the 2012 was 160*-170* UNDER EXACT SAME conditions. My dealer, who is awesomwe, has no answer at this point. FYI

BigRock33
You are the post that I was waiting for. I was trying to verify that indeed the 2012's compared to previous years are running hotter across the board (with a few exceptions). Thats what I am seeing. I am wondering why? Lean in the bottom end? Restriction in the sytem? I am well aware that scratchers will remedy the problem. Being in the rental business I witness more sleds and conditions of 99% of the average sledder, day in and and out. I would appreciate any feedback from those who have a 2011 and 2012 to compare. From what I am seeing I believe there is a problem. Never had this problem with standard model Polaris RMK's in the past ten years. Thanks for you input.

 

[The Fourth Wolf]

rockinm,

If you're running new poos as trail ride rentals you're asking for problems IMO.

I'm no expert but I have a 2012. 20 miles of my first ride was on a tight, twisty, up & down trails through thick woods interspersed with occasional open runs across ponds and lakes. Conditions were decent--4" of soft, beat up snow on a good base--but my machine ran hot most of the time.

What I noticed was 10-15 mph at 4800-6500 rpm was the zone where the temps shot up fast but whenever we hit a straight stretch of trail or a pond...as soon as I opened it up and my speed hit 25+ MPH the temp dropped immediately. My sled ran a steady 125* at speed.

The important lesson I learned is...I will NOT be taking my Pro out on rides that I know will be predominately slow-speed trail rides.

My guess based on my experience is the stop and go riding style of your customers is keeping your machines in the rpm range to maximize heat loading without getting them to the speed where cooling begins.

Were I you I would not rent the 2011/12 Poos on days when hardpack is the dominant snow condition. I know that sucks, as they'll be sitting idle and not making you money, but better that than a bunch of new sleds with burned down motors due to overheating.

Maybe multiple sets of reverse-proof scratchers on each machine? Or a separate $60 mini-deposit on the scratchers? The old "you break em, you bought em".

 

[rockinmranch]

As much as I agree with what you are saying, that is like saying your 4x4 pickup should only be operable off road but doesn't work on the pavement. As much as we would all love to ride powder from the pick-up, realistically most people have to ride some trail to get to the powder. I don't believe that this is just the way it is, but that something is wrong. That said, what is differen't from last years models? Remember all of my sleds are standard RMK's not the Pros? My 2011 pro rmk runs cooler than these new standard model 2012's!!! Something is differen't (not right). What is it? If Polaris was aware of this issue, wouldn't it makes sense that the standard model RMK's would come with scratchers as stock equipment like the pro RMK's?

 

[jdw1]

I don't know how last years standard rmk's cooling system was configured, but I looked at putting the close off cooler on my pro and the interesting part was that the close off cooler on a standard rmk is not plumbed in a series with the rear coolers, the top hose comes off of the bypass port down to the cooler and then back out of the cooler to the recovery tank, it really didnt make sence to me how Polaris has that configured. FWIW.

 

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[camocat1000]

2012 are using a different plug to help from fouling plugs...someone that know more about plugs can chime in..it could be a hotter plug idk about causing to motor to run 40 to 60 degrees hotter

 

[jdw1]

2012 are using a different plug to help from fouling plugs...someone that know more about plugs can chime in..it could be a hotter plug idk about causing to motor to run 40 to 60 degrees hotter

I think that they are the same heat range.

I just looked up the parts for the cooling system for the 2011 and 12 model years and they are the same.

 

[wyodragon]

Bought the Pro last year and realized immediately it does not cool like the dragon. You have to pay attention to temps with the new sled and I agree with others ,this is going to be a problem for rental sleds. You have to have scratchers and operate in the right rpm to keep some snow moving. The right rpm range is a little faster than most renters are comfortable.I have never gone farther than Little Greys down the trail and I get off and find some powder every chance I get. 50 yards of powder at midrange will cool it right down to 125.I think if you rent one to somebody and they try to piddle around up the trail to Box -Y its going to overheat and shutdown a bunch. My brother rented a pro last year that had no scratchers and it shut down before squaw creek trail running right beside mine with scratchers. Mine will typically run about 155-160 down the trail,and constant 125 in powder.

 

[Bigrock33]

Ran both sleds today North Slope Uintas - very marginal snow, same results as previously posted. Ran with scratchers down, 167* for a high temp on the 2012 and 141* high temp for the 2011. That was going up twisty,windy road for about 3/4 mile with not a lot of loose snow. Also have extra bogey wheels on both. Definitely a difference.

 

[enis750]

I rode about 26 kms of trail tonight on my 2012 base proride RMK
Mostly hard pack trail some loose stuff
No scratchers down and never saw higher than 128
W scratchers down never above 123

Glad i got the base model

 

[Merlin]

I don't know how last years standard rmk's cooling system was configured, but I looked at putting the close off cooler on my pro and the interesting part was that the close off cooler on a standard rmk is not plumbed in a series with the rear coolers, the top hose comes off of the bypass port down to the cooler and then back out of the cooler to the recovery tank, it really didnt make sence to me how Polaris has that configured. FWIW.

I agree, it does seem odd....................

According to what I can interpret from the on-line parts manual, it appears that the coolant would only circulate through the front cooler until the thermostat starts to open..........Once the thermostat starts to open, coolant would begin to flow through the rear coolers.............After the thermostat is completely/mostly open, the majority of the coolant flow would be passing through whichever circuit has the least resistance............

It would seem that the system might be more efficient if the front & rear coolers were plumbed in series???

 

[Oehlke Farms]

Maybe the tipped up rails on the 11s fling more snow on the tunnel vs the 12s straight rails.

 

[Butta]

Maybe there's a difference internal to the cooling passages in the cylinders? I think there are different part numbers for the cylinders between '11 and '12, but have not verified that yet. Maybe it's Polaris's attempt to minimize the "cold shot" effect on the motors...?

 

[Zrider]

take a 5/16 or 3/8 bolt and install in the rear of the ski's pointed down to act as a scratcher(should just penetrate the ground when sitting on flat ground..)i have seen guys cut 1/2 way thru the bolt to allow it to snap off if it hits anything too solid so it doesnt hurt the ski..but that should get some good snow spray under the track and help cool it down...cheap,easy scratcher that wont care if it gets backed up on as well..

AK:

Any chance you could post a pic or 2 of your install?

 

[Reg2view]

Maybe there's a difference internal to the cooling passages in the cylinders? I think there are different part numbers for the cylinders between '11 and '12, but have not verified that yet. Maybe it's Polaris's attempt to minimize the "cold shot" effect on the motors...?

They are different cylinders to accommodate the injector design and vendor change from 11 to 12. Crap shoot from there, you never know the whole story with poo.

 

[deschutes]

It looks like there is still some confusion, so to reiterate what rockinM said - he is not running pros, the 2012 rentals are standard RMK's. He has a 2011 Pro he is comparing them to.

Rockin - I rode your Pro last year, it is what made me decide to buy a 12 Pro. Your sled did run a little warm on the ride in/out, but nothing like my 12. If I am not moving at a good clip with the scratchers down the temps shoot up drastically and quickly. I have attributed this to break-in, hopefully, but it seems almost unnatural. More snow, more miles and time will tell. Not the side by side you are looking for, but my gut has been telling me that the sled runs hot.

 

[rockinmranch]

I agree, it does seem odd....................

According to what I can interpret from the on-line parts manual, it appears that the coolant would only circulate through the front cooler until the thermostat starts to open..........Once the thermostat starts to open, coolant would begin to flow through the rear coolers.............After the thermostat is completely/mostly open, the majority of the coolant flow would be passing through whichever circuit has the least resistance............

It would seem that the system might be more efficient if the front & rear coolers were plumbed in series???

This is very intereating. I am going to check into this with my dealer here in a few days. Thanks!

 

[Oregonsledder]

It looks like there is still some confusion, so to reiterate what rockinM said - he is not running pros, the 2012 rentals are standard RMK's. He has a 2011 Pro he is comparing them to.

Rockin - I rode your Pro last year, it is what made me decide to buy a 12 Pro. Your sled did run a little warm on the ride in/out, but nothing like my 12. If I am not moving at a good clip with the scratchers down the temps shoot up drastically and quickly. I have attributed this to break-in, hopefully, but it seems almost unnatural. More snow, more miles and time will tell. Not the side by side you are looking for, but my gut has been telling me that the sled runs hot.

Ben I have 170 miles on my 12 PRO and have found the relationship between speed and the need for the scratchers a bit interesting. If the snow is hard, it takes more than just having the scratchers down to keep the temp below 160. If you are going around 15 miles an hour or so, on hard snow with the scratchers down, the temp goes up very fast. Move the speed to 25 or 30 and it drops just as fast. It seems the coolant flow through the system is not adequate at lower rpm's. It's hard to imagine that there is that much more snow spray on the exchangers?? I wonder if the water pump flow rate is as much of an issue as the amount of heat exchanger surface area? This is a great sled, but I like to boondock in the trees and many times that means working slow around things. I suspect it's going to be hard to keep the temps down under those kinds of situations on hard snow days.

 

[veritascs]

200? your cooking the thing. get scratchers on it. should stabalize at 120-130
temp lights flash at 167

Not on my 2012, I towed some gear into a yurt, was running on not much snow, slow speeds, uphill, was hitting 190 degrees with no temp light.

To rockinmranch, I went riding the other day and noticed temp gains of 20 degrees on a freshly groomed trail when I didn't have scratchers down. I'm guessing that difference would be higher on even harder packed snow. I'd suggest getting scratchers and also waiting until some fresh snow to make any real judgements. .02

 

[Zrider]

OS:

Springtime tree riding on firm snow is a big problem. I would have to continually stop and pack snow on the top of the tunnel to cool things off.