The fix on the Pro

[beamslayer]

Has anyone tried the fix from PMS on there pro yet? I talked to Shawn today and he said they have sold quit a few so I am just seeing if anyone on here has tried it. I know it really helped out my friends dragon but has anyone have over 1000 miles on one yet ?
In are conversation he said it works really well with the Power Addiction head also.

 

[KAWGRN]

I have one on my 11 pro all season! Its quiter! I did it so that I could do some port work,plus I felt that the billet steel base spacer gave my cylinder skirts some needed support as they were real tight going on as well as the lip that went into the case,, I felt the whole package made the engine from top to bottom more rigid, the longer piston I feel stopped the rocking into the exhaust port causing skift breakage,JMO though

 

[beamslayer]

If you are looking for a good laugh do a search on the PMS Kit on here. Alot of those people that were bashing them for saying it was a fix for the pro are in another post on here like who lost a skirt, or 11 &12 reliability.

 

[KAWGRN]

So are you saying the pms kit doesnt work?? And I do have a pa head on mine! But with the slp cold air intake I ran into deto issues and will drop back to 12.9 head, the weisco piston that pms uses is a different crown than a stock piston!,,I belive this kit has wayyyy more advantages than just a piston kit!

 

[beamslayer]

No I am not saying nothing bad about there kit matter of fact I am looking into it. I just had to laugh at all those who jumped on there chit. Nothing wrong with the 800 pro, now most of them are on here telling how there motor blew out the cases.
Thanks for the reply and how did your porting turn out.

 

[KAWGRN]

Porting turned out well, it wants to rev higher I think I now need a pipe to take full advantage of it its more like a dragon port now!I feel the pro port is shaped to give good piston support ,,not power!

 

[Jimb]

I was considering a piston change, but I question the reliability of any kit. Putting in lighter pistons and then spinning the motor up to 8300 rpm is kind of like the old pipe trick more hp because of increased rpm but no increase in torque. Really no big gain for mountain riding where torque is king.

I think the Internet overplays the whole kaboom issue.

 

[Norway]

I was considering a piston change, but I question the reliability of any kit. Putting in lighter pistons and then spinning the motor up to 8300 rpm is kind of like the old pipe trick more hp because of increased rpm but no increase in torque. Really no big gain for mountain riding where torque is king.

I think the Internet overplays the whole kaboom issue.

You may be right, I hope so cuz I run a 2011...

But I've been on this site since the flip of the millennium, and I cannot recall anything close to this bad feedback on a stock engine.

Sure, the growth in members could sift out more people with troubles into a thread like this and the % of motors going down COULD be within normal.

IMHO this is not the case. A year ago I talked with a reputable modshop about my concerns and was told to replace pistons within 2000-2500 miles depending on state of tune. Now, his number is down to 1000-1500 miles...

And last, looks like you're missing the point on the fix kit. It's all about reliability, any added power is just a benefit. A longer piston with better clearance means less rocking of the piston, not slamming those cylinder skirts so much, and less wear from piston sideload.

Mine is at 620miles and counting..

 

[edavis0202]

I was considering a piston change, but I question the reliability of any kit. Putting in lighter pistons and then spinning the motor up to 8300 rpm is kind of like the old pipe trick more hp because of increased rpm but no increase in torque. Really no big gain for mountain riding where torque is king.

I think the Internet overplays the whole kaboom issue.

Less weight means, less drag on the crank...therefore less effort on all moving parts.

Just because something is less weight doesn’t mean it’s weaker...example: Titanium, carbon fiber

This would fix the problem with skirts breaking…

As far as HP and torque…you will gain some but not worth braggin about

 

[beamslayer]

I wish some of the other aftermarket guys had more time on there kits so we could have a better comparison . But at this time the fix has the most miles and most of them are with the cfi4.
If you have a warranty it is a no brainer just let polaris fix it but some of those warrantys are running out.
The whole skirt issue is mind boggling why some last and some go out after 500 miles.
If it is as simple as lighter pistons,longer rods or a shim and longer pistons why wouldn't poo correct it ?
If I could buy a warranty for what it will cost me to install one of these kits I would and let polaris take the hit.
I am on the fence between RKT and The Fix kit so please voice your opinions.

 

[tdblakes]

I'm planning on going with RKT because he has a long running reputation with Doo, kit includes a head, tuned for stock exhaust & no fuel controller, designed for & tested on the CFI2, those running it claim a nice power jump & overall smoother running motor, offers the cheater head style for $100 less so I can get low altitude and high altitude domes... my .02

 

[KAWGRN]

I was considering a piston change, but I question the reliability of any kit. Putting in lighter pistons and then spinning the motor up to 8300 rpm is kind of like the old pipe trick more hp because of increased rpm but no increase in torque. Really no big gain for mountain riding where torque is king.

I think the Internet overplays the whole kaboom issue.

That depends on blow down time and port width I never said I was spinning the motor up at 8300 ,Im saying a pipe will compliment MY porting,I guess SLP has it all wrong then??

 

[gman086]

That depends on blow down time and port width I never said I was spinning the motor up at 8300 ,Im saying a pipe will compliment MY porting,I guess SLP has it all wrong then??

I believe he was referring to the RK-Tek kit which Kelsey typically likes to spin at higher rpm's.

Have FUN!

G MAN

 

[Jimb]

Kowgrn I wasn't addressing your post just cooincidnece i posted after you did.

I was looking to generate some dialog on sticking with Polaris parts trusting the Polaris engineers or trust a couple shops who make claims of improved parts but have relatively few kits out there vs the number of sleds sold.

 

[KAWGRN]

I dont trust Polaris engineering as I lived through the CFI-4

 

[RKT]

I will try and address a few things..

1) We run the BONE STOCK pro at 8350 (it does run MUCH better at that rpm) we run our drop in kit and our big bore kit at 8350... So the rpms have not changed
For those who think that there stocker Pro runs better at anything under 8350.. all I can think is that they have never ran it at 8350 to notice the difference... W ehave tested the rpms from 7900 to 8600 and there is no question where this engine runs the best.
So, in short.. no big rpm change with the RK Tek kits (either the 858 or the drop in kit)..just a difference in opinion on where this engine performs optimum.. rpm wise..

2) Lifting the cylinder on this engine will change crank case volume which we have found to hurt performance, especially, at the higher elevations..

3) Lifting the cylinder on this engine WILL LESSEN Piston support which WILL increase piston wear and WILL place more stress on the skirt of the piston and the cylinder.

4) The 858 kit was new this season and has a over 1200 miles on it with no issues and substantial power increases.

5) The drop in kit has been installed in MANY sleds and most of them have over 1500 miles on them with ZERO issues and very nice power gains.. The Engine loves this kit and it does deliver power and does address some internal issues. So, you get more performance and fix some internal issues in the process.. What is not to love?

6) Lighter pistons will always lessen stress on components..

Hope this clears a few misconceptions that are appearing regarding the RK Tek kits.

Kelsey

 

[KAWGRN]

2) Lifting the cylinder on this engine will change crank case volume which we have found to hurt performance, especially, at the higher elevations..


I have to disagree as The motor was designed as a 600 and the factory race sleds increase crankcase volume any way they can I belive the lack of volume is one of the reasons this motors not in the 160's like the rest

Lifting the cylinder on this engine WILL LESSEN Piston support which WILL increase piston wear and WILL place more stress on the skirt of the piston and the cylinder.

that depends on the piston configuration! But this JMO

 

[Scott]

Less weight means, less drag on the crank...therefore less effort on all moving parts.

Just because something is less weight doesn’t mean it’s weaker...example: Titanium, carbon fiber

This would fix the problem with skirts breaking…

As far as HP and torque…you will gain some but not worth braggin about

Titanium is a SOFT metal.
Light? Yes.
Rigid? No.
Strong? Easily debatable depending on how it is used. In clutch springs, yes. A-arms? Hmmm. Not sure.

 

[beamslayer]

So far Kawgrn is the only one that has come on here with real world experience.Kelsey by no means am I here to bash I just want to here from those who have run your kit on the pro.
I was just contacted by a guy in Washington who wanted to compare notes on these kits what are the pros and cons. We both agree they address the skirt issue but from different theory . With out any real hands on it is hard to compare.
Can someone explain the theory of case crank volume and does it differ from carb or injected fuel on how it performs ?
Does adding a shim add strength to the skirt or is it to add just height ?
I understand how lighter pistons would create less stress but are you also moving the wrist pin to help with the side load. Not looking for trade secrets.
The million $$$ ???? Why do some go at 500 miles and than some run to 3000 + miles it just does not make any sense to me. Maybe it has nothing to do with pistons just faulty cylinders and poor expansion and the skirt is the weakest link?

 

[Reg2view]

The million $$$ ???? Why do some go at 500 miles and than some run to 3000 + miles it just does not make any sense to me. Maybe it has nothing to do with pistons just faulty cylinders and poor expansion and the skirt is the weakest link?

FWIW, the OEM stock piston clearance varied alot on 800's from motor to motor. How the motor is actually run on the snow varies, too. It's been mentioned before, but the short track 800 failures are reportedly pretty thin with both the CFI4 and CFI2. It's a combo of two or more factors in the end. Those are the hardest to fix retroactively, short of a new, tested design.

There are CFI4's out there that have never failed; I have a buddy with 3.5k miles on his stock (air box mods only) 10 IQ RMK 800 CFI4. I think he's nutz, but he plans to run it again in 12-13 just the way it is.