The Get your FIX for the RMK 800

[t stone]

I havent pulled it apart yet. Its still stuck. I put some penatrating oil in the hole, letting it sit. I will call Shawn to discuss my options. Thanks for the help.

Stone

 

[gerrman]

"Ordered a PMS kit a week or so ago. Waiting for it to clear customs. My '09 RMK is my second of the bad motor machines. The '08 was crap, but the '09 has held together. I contribute that to heat sinking the motor 3/4 times, not using the old VES oil, and ALWAYS warming the engine to 100* before I move it. It has 1250 miles over the last two years and I would bet dollars to donuts that the pistons will look great when I pull them. However, I still feel that it is a ticking time bomb and that is why I went with the PMS Kit. Need to keep this thing for at least 2-3 more years. Will keep everybody posted as changes take place."


Well I pulled my engine and took it apart this week. I could not of been more wrong on what the pistons looked like. Both were scored on the intake side, outside skirt tab of their respective cylinders. The Mag side was the worst, a significant three line score, a fat 1/4" wide and about 3/4" long. Cause, must be when the piston cocked in the cylinder at BDC and hitting the cylinder skirt on the way up. Cylinders are fine though. Took it and the Wiseco's to the Machine shop this AM to have it deglazed, clearance's checked and rings end-gapped. Engine is not off warrantty until the end of Oct. 2011, dealer is going to work with me on this repair. They have the pistons now. That was with 1250 miles on the motor. I am so glad that I decided to this "FIX" otherwise I am sure it would have blown sometime this season and I would have been SOL.

 

[gerrman]

Well I pulled my engine and took it apart this week. I could not of been more wrong on what the pistons looked like. Both were scored on the intake side, outside skirt tab of their respective cylinders. The Mag side was the worst, a significant three line score, a fat 1/4" wide and about 3/4" long. Cause, must be when the piston cocked in the cylinder at BDC and hitting the cylinder skirt on the way up. Cylinders are fine though. Took it and the Wiseco's to the Machine shop this AM to have it deglazed, clearance's checked and rings end-gapped. Engine is not off warrantty until the end of Oct. 2011, dealer is going to work with me on this repair. They have the pistons now. That was with 1250 miles on the motor. I am so glad that I decided to this "FIX" otherwise I am sure it would have blown sometime this season and I would have been SOL.

Got my cylinder and pistons from machine shop last night. Clearance on the Wiseco's are between 0.0049" and 0.0051". Minimum is 0.004" from PMS install sheet. The OEM used pistons were 0.009". Ring end-gap is 0.019" and 0.020". Minimum is 0.018" from PMS install sheet. Will be putting it back together this weekend.

 

[JakeR]

Well guys I have and 09 that I bought from carls and It had the 10 update and after taking the time to read all this thread I got to thinking... So tonight I pulled the ev's and sure enough the mag side piston is scored.. Its not bad but im sure it would of let go this season.. So today I called Shawn and he answered every question that I had and more that I didn't even know that I had. So we came with a decision that im going to order the "fix" and then Im going with there billet head and the 08 map.. Im sending the ecm and cylinder to shawn and he is going to break the glaze and reflash to the 08 map then send it back to me. Im going to block the ev tube off and run the pink springs. I love this sled I just want to know its going to be ok.. Thanks Shawn for all the answers and I will keep you guys updated!!!

 

[IDPOLARIS]

Tell us more about there billet head shawn is a top notch guy and he is the only one that i will let work on my sled's period.

 

[gerrman]

Got my cylinder and pistons from machine shop last night. Clearance on the Wiseco's are between 0.0044" and 0.0046". Minimum is 0.004". Ring end-gap is 0.019" and 0.020". The OEM used pistons were 0.009". Will be putting it back together this weekend.

Put the cylinder and pistons back together last night. Did a squish check. Was 0.069" and 0.070". This just happened to be the same measurement I got with the stock upgrade pistons and head. The "Kit" was to tigthen the squish up approximately 0.005". Called PMS to double check, they confirmed my suspisions that it may be factory manufacturing tolerances coming into play here. Reason for the concern is that I am putting on a Power Addition head. Will cc the head chamber for FTX as they asked and talk to them again on Monday to hopefully get things ordered.

 

[JakeR]

I dont know much about the head as of right now but will ask more the first of the week. Basically shawn recommended the billet head cause it is hard to find the 08 heads and I want to run the 08 head and map. Pulling mine down tonight and the cylinder looks great I caught it in time but the pistons have .010 clearance...

 

[gerrman]

Put the cylinder and pistons back together last night. Did a squish check. Was 0.069" and 0.070". This just happened to be the same measurement I got with the stock upgrade pistons and head. The "Kit" was to tigthen the squish up approximately 0.005". Called PMS to double check, they confirmed my suspisions that it may be factory manufacturing tolerances coming into play here. Reason for the concern is that I am putting on a Power Addition head. Will cc the head chamber for FTX as they asked and talk to them again on Monday to hopefully get things ordered.

Did the Install CC and came to @34.5 cc's. Be aware of the plug boss in the chamber, it will screw with the initial instalnumber, you will have to measure that seperately (@4.5 cc's). Ordered the Power Addition head and motor plate today. Should have that in two weeks and then back together the following weekend. We have had heavy wet snow here @ +3000' over the past few days. That is good news!!!

 

[kmo]

Did Polaris resolve the excessive piston to cylinder clearance issues in the 2011 800 engine?

Also, does "The Fix" resolve the Cylinder skirt cracking issues that the '08-'09 800's are developing?

 

[gerrman]

Well, I finally got my engine completely back together and installed yesterday. Head and engine plate got hung up at customs. They must have been on a five day coffee break. Did final checks this AM and fired her up. Engine started fourth pull and purred perfectly. Sounded very crisp and strong. That loose somewhat rattley sound was missing. Warmed her to 126-128. Will do another heat soak Monday. Hope to do a test ride in two weeks.

 

[IDPOLARIS]

That is good to hear i can't wait till mine is done what was your finial squish with the power addiction head...

 

[gerrman]

That is good to hear i can't wait till mine is done what was your finial squish with the power addiction head...

Squish ended up to be 0.62". I double checked with FTX on this measurement. It is good to go. Just for info, the squish measure with the stock head and Wiseco pistons was 0.069". So it tighted up 0.007". Heat soaked the motor again tonight. One more time and she will be good to go.

 

[bigfeet]

08 800 dragon

Here is the original post from PMS Polaris / MTNTK as seperated by Diamondave and then copy and pasted.

Originally Posted by MTNTK

I appreciate the comments on our products, but there are a few things your not getting quite right. Polaris built this motor to be very compact and lighter than previously designed engines. This being said there were compromises made that they thought were "acceptable".


One of those were to shorten the piston as much as possible. This kit is not a rod ratio change nor does it fix a rod ratio. it does not use pistons with a higher rod location to allow a longer rod to change thrust loading. Nor has any of our research found that the polaris engine had improper thrust loading on the piston.



If the thrust loading problems were true, then you and i would have seen scoring and piston damage on the thrust side of the pistion/cyl. I have never had a problem with the thrust/intake side of the piston. It always looks good, but the exhaust side looks really bad. But it is interesting to look at the design of the polaris engine, because it looks like an engine that they were trying to eliminate rod thrust loading because the stock piston has a rod pin location that is high on the piston almost like they were trying to get the longest rod possible without getting any deck height increase.



What our kit does do is raise the cylinder up and allow us to put a taller piston in the cylinder. What we found is that the polaris engine has excessive piston to cylinder clearance. this allows the piston to rock in the bore effectively using the top and bottom edges of the piston instead of the entire bearing surface of the skirt.


I have a very reliable source that stated polaris had a severe piston heating problem in the prototyping of the engine and so they elected to go with increased clearance to prevent piston seizure. This heat problem was fixed with the ecu reflash. The clearance combined with the piston design causes the piston to scrape the cylinder wall on the compression stroke, especially the exhaust side.


This is why the piston looked like it ran out of oil on the exhaust side but not the intake. This is why the engine would never totally fail, just slowly start to run bad, not going into reverse and then hard to start and then put, put, put and barely back to the trailer. This is also why there was an interesting phenomenon that when using a turbo on this engine it would last longer than stock. Everyone thought it was a fuel issue, but it was not. It was a piston size problem. The turbo added heat and the piston grew taking up the clearance.


The taller piston benefit can be easily described by the analogy if you have a smart car(which is a very short car!) on a single lane highway it would be much easier to turn around without going off the road than it would be to turn a tractor trailer semi (a very long vehicle)around on the same road. The piston does the same thing. It can't move away from the cylinder wall nearly as easy if it is longer and has tighter clearance than the stock piston. This makes horsepower in more than one way.


The first way is because the piston is not leaned over it holds cylinder pressure longer and makes the power stroke longer. The second way is the piston is 40 grams lighter so there are not as much parasitic losses internally. Third and less known is the piston slap is reduced and excessive piston slap can set off the detonation sensor and back off timing. fourth is the previously stated crankcase volume increase, which has been proven in numerous sae studies with tuned pipes is almost always beneficial for engines designed for peak power.



On our dyno it made 4.9 hp more and that was on a totally stock 2010 engine, airbox, and fuel. I hope this sheds some light on the product and I hope you can have some faith in it that we don't just come up with some gimic or "widget" and sell you on it. We test, we prove, we cannot sell you something we do not believe in. I welcome any more questions. Shawn, Mountain Tek Performance.

so when this kit gets put in do they need to turn the oiler back down also cause i know on my "fix" from polaris they turned it up and i think re mapped the the sled .do i put everything back to factory with the new pistons or what do i do now before it probly starts to blow up again ??? check engine light is flashing already with 300 miles on motor .flashing 7 times soon as i start it but seems to run good .not sure what to do anymore with this dang sled !!!!!!!!!!!maybe you can tell me .thanx

 

[IDPOLARIS]

hope this will help..

 

[harrysmith500]

Have their been any engine failures with guys running MTNTK's fix kit?

My sled has the fix with the SLP head.
I have 400 miles on it.
I compression tested it last night, 140 PSI, both cylinders.

 

[diamonddave]

Have their been any engine failures with guys running MTNTK's fix kit?

My sled has the fix with the SLP head.
I have 400 miles on it.
I compression tested it last night, 140 PSI, both cylinders.

I've only heard of 2. This season will be the telling part as the miles and time starts to rack up.

Another cool thing is there are other, less known vendors offering their version of a better top end kit for the 800 CFI.

 

[gerrman]

Put my first 40 miles yesterday on the "Fix" and 12.5 Power addition head. Fouled two sets of plugs though(Champion), not sure why. Will buy a set of pricey NGK's and try them in two weeks. Engine ran fine otherwise. Had a snappier feel in the mid range, that is the head. Temp was a steady 126, just like before. One more tank of mixed gas and it will be time to cut her loose.

 

[harrysmith500]

I fouled a bunch of plugs when I broke mine in as well. I was running super duper rich with lots of oil in there.

 

[gerrman]

I fouled a bunch of plugs when I broke mine in as well. I was running super duper rich with lots of oil in there.

What plugs are you running? Mine was super rich as well. Was at 2700-4100'. Air had lots of humidity in it as well. PCV with ethanol wires plugged in.

 

[harrysmith500]

I fouled NGK BPR9ES.
After I ran that tank and got the crazy oil mix out I went to The NGK iridiums. I'm mixing 1/2-3/4 ounces of injex to each gallon of gas.
On the break in tank it was easily over 1 ounce of injex to each gallon of fuel.

I'm now running about 20% VP110 leaded.