Fix Kits!

[rmk727]

Originally I didn't pay close attention to the threads and thought I was getting the RKT fix kit but wound up with the MTNTK kit and personally I love it. Put it in an 08 Assualt that was down. WOW the power is awsume. We now in our shop put these in all our used sleds and advize customers to follow up and do it before the engine fails. They run $700.00 installed and we've run em all season no failures yet; only problem is getting them; they are always out of stock.

 

[beamslayer]

I also run the mtntek kit in my pro and am very happy with it. I too was going with RTK kit but I already had a PAR 13/1 head and hps can .
I would love to try out the drop in kit from Kelsey just for comparison .
It seems that most kits are performing well and after next yr when they start getting close to the 2000 mile mark we will see than .

 

[dragonfire]

Originally I didn't pay close attention to the threads and thought I was getting the RKT fix kit but wound up with the MTNTK kit and personally I love it. Put it in an 08 Assualt that was down. WOW the power is awsume. We now in our shop put these in all our used sleds and advize customers to follow up and do it before the engine fails. They run $700.00 installed and we've run em all season no failures yet; only problem is getting them; they are always out of stock.

Another good option that I have heard good reports on also.

 

[Jeffdutch123]

I've been running a fix kit in my 11 pro for the last few hundred miles and have had no issues at all. I gained a couple hundred rpm and engine runs much smoother. I ordered my kit off eBay, it is actually called the dragon fix kit and the cylinder shim was a little different but for 430$ you can't go wrong, a die grinder and 15 minutes fixed the spacer and the kit is available with wiesco or cast namura pistons, I think the namura kit is only 385$.

 

[locknload]

When I put my dragon engine back together I was advised by a local engine builder to use one of his cast pistons, 30 grams lighter then stock, cylinder from mellinium, meticulous with the piston clearance and ring end gap. This motor flat out runs and is idles much smoother then stock. I have a friend with the mtntek kit (awsome customer service) which also runs very well but he hasnt been able to come close to mine in a drag race, and yes clutching, pipe, fuel map, pc-v, everything identical. That is why I believe Kelsey is on to something when he talks about the lighter pistons. I have also installed one of Indy Dans motors in another friends dragon and it is probably the smoothest running engine ive ever seen but have not had the opportunity to run against him yet.

 

[GoBigParts]

So this may be a dumb question but I am also trying to decide what will be best for my next move. Does the piston shrink overtime? I keep hearing how with just a few hundred miles on them the piston to cylinder clearance is getting to large.

I have extended warranty and have been talking with my dealer. He is telling me that they measure the cylinders and everyone they have checked while doing a rebuild is at the low end of the tolerance meaning the clearance can't go any smaller.

 

[rmk727]

Paul ; go into the dealership and ask if they are working on any motors and if so if they will let you see one. Take a new Polaris piston without rings and put it in a cylinder hole. The slop is tremendous so much that in the old days of fuji motors you would be putting in oversize pistons, that is what the fix kits fix.

 

[GoBigParts]

Paul ; go into the dealership and ask if they are working on any motors and if so if they will let you see one. Take a new Polaris piston without rings and put it in a cylinder hole. The slop is tremendous so much that in the old days of fuji motors you would be putting in oversize pistons, that is what the fix kits fix.

Based on the reading I have done that I what I would expect to see as well. I have also heard the cylinder clearance is not very consistant. So I am still confussed if it is the pistons or the Cylinders or if it even matters. One seems to fix with different pistons the other addresses cylinder size. If I had to guess cylinder size would seem very more than piston size. If I took 2 new pistons out of the box would they be the exact same size? If I took 2 brand new cylinders out of the box would they be the exact correct size? I would think the only way to fix it right is to have both sized to each other. So I send my pistons out with my cylinders and have the cylinders sized to my pistons.

Therefore if I buy new aftermarket drop in pistons How do I know the holes I drop them into are the correct size wth out having all of the above done? I guess the pistons can not just be purchased and dropped in there may be other costly work that has to go along with it.

 

[gerrman]

Hopefully will be updating to a 2012 Pro from my 2009 Dragon at the end of April here(low mileage 2014 trade). First thing I will do to the Pro engine is install a MNTK Kit. I put one in my 2009 Dragon at 1200 miles(engine was good) and now has 2000 miles on it. Runs like a charm.

 

[rmk727]

Paul; I have not heard of the holes being wrong but they should always be measured. the stock pistons are the problems , but remember with the kits the new piston is bigger everywhere so it's not a piston buy its the kit that includes the spacer under the cylinder, lots of back threads on what this does, also controversy on it with Indy Dan, but as far as I can tell his way is great and so are the fix's with the spacer. His is much spendier but time will tell if it lasts longer.

 

[beamslayer]

Paul take your cylinder to a machine shop or a good aftermarket bike shop and have them check your cylinder for dia,out of round and taper . Take your engine spec sheet with you or manual . Look for cracks at the bottom of the intake side of the skirt ,some are really hard to see . If everything checks out have them use a straight engine hone made for nicasil and rough up the cylinder with a good cross hatch . Wash cylinder out with simple green/hot water and wipe out with atf and a clean white cotton rag .
Order the kit of your choice and check piston clearance with a feeler gauge on the front or rear of piston not the side and at the bottom of the piston not the top. .045 to .006 I believe is spec but check with your manual or the peeps that you get your kit from . Than check your ring end gap ( ring end gap usually goes towards the intake ) so if it goes the other way pistons are on wrong.
Ask your dealer how they measure cylinders ( correct answer is a bore gauge ) anything else find someone who does . (machine shop-aftermarket Harley shop )
I hope this helps.

 

[sledheadd]

What I want to know is how long can you run these drop in kits before needing to change the pistons? How many miles?

 

[theshadowrider]

Based on the reading I have done that I what I would expect to see as well. I have also heard the cylinder clearance is not very consistant. So I am still confussed if it is the pistons or the Cylinders or if it even matters. One seems to fix with different pistons the other addresses cylinder size. If I had to guess cylinder size would seem very more than piston size. If I took 2 new pistons out of the box would they be the exact same size? If I took 2 brand new cylinders out of the box would they be the exact correct size? I would think the only way to fix it right is to have both sized to each other. So I send my pistons out with my cylinders and have the cylinders sized to my pistons.

Therefore if I buy new aftermarket drop in pistons How do I know the holes I drop them into are the correct size wth out having all of the above done? I guess the pistons can not just be purchased and dropped in there may be other costly work that has to go along with it.

I had the same question on my dragon engine. I measured both stock pistons and they where different sizes. I also measured both cylinders and they where both exactly the same. The pistons had different wear patterns. The bigger piston had more of the coating warn off. New weisco were both the same size. I am not a fan of OEM pistons or a fan of cast pistons. Forged piston is much stronger and more resilient to abuse.

 

[gman086]

What I want to know is how long can you run these drop in kits before needing to change the pistons? How many miles?

If everything is in tolerance, 3,000 miles normal use, 2,000 miles mtn. use is the general rule for two strokes on the conservative side. Add 1,000 miles to those numbers if you're feeling lucky tho I usually run mine out to 3,000 miles (but I run extra oil in both tank and turn up the oil pump so YMMV).

Have FUN!

G MAN

 

[Coleniuk]

Thanks for all the info on the kits guys! Much appreciated!

 

[aebsledder]

Good thread

Good info here. I am hoping for another good 2 months of snow so more people can get some actual miles on their sled to reach the magical realm of snowmobile "reliability", which I am convinced is a ludicrously low number. (If you read the forums)
I.E. Snowest guy- "I have almost 250 miles on my brand x kit and no problems!"

I am going to pose the question this summer and see if anyone has around 1500-2000 mountain miles on their fix kit. I could live with that.

 

[RKT]

Good info here. I am hoping for another good 2 months of snow so more people can get some actual miles on their sled to reach the magical realm of snowmobile "reliability", which I am convinced is a ludicrously low number. (If you read the forums)
I.E. Snowest guy- "I have almost 250 miles on my brand x kit and no problems!"

I am going to pose the question this summer and see if anyone has around 1500-2000 mountain miles on their fix kit. I could live with that.

We have MANY drop in kits that are far past the 2000 mile mark..

Longevity is built into our design... They will go 3K without issue...

 

[assault11]

Good info here. I am hoping for another good 2 months of snow so more people can get some actual miles on their sled to reach the magical realm of snowmobile "reliability", which I am convinced is a ludicrously low number. (If you read the forums)
I.E. Snowest guy- "I have almost 250 miles on my brand x kit and no problems!"

I am going to pose the question this summer and see if anyone has around 1500-2000 mountain miles on their fix kit. I could live with that.

I had over 3000 with my stock 11 motor and it was still fine

 

[beamslayer]

That is great 3000 miles . Those are the miles I would like to see out of a Poo engine . Anyone else see these miles.

 

[assault11]

That is great 3000 miles . Those are the miles I would like to see out of a Poo engine . Anyone else see these miles.

We had another 11 with almost 3000. It was awesome. And we have a 12 with 2300 trouble free miles. Only thing done to the sleds was a par 13.1 head