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Which top end?

Which top end should I put in? And should I do it myself or pay to have it done?


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    153
B

boondocker155

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Sep 5, 2013
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I did the mtn tek kit. I would recommend it for sure. I will put it on my next sled again.


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mtncat1

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Oct 19, 2008
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south jordan ut.
I did the Mntkt about the same miles as you. Zero issues before like you but it was never stock. IMO a controller on a '13 adds power and life but you are the proof it can survive without it too lol.
My stock pistons were only 1 thou smaller than the replacements so my pistons did not collapse but the rings and lands were worn. I had ordered and purchased the kit before I took it apart so installed it. Had I taken it apart first I may have cleaned up the ports (reason for my ring failure not piston rock) and gone stock again. the CFI port configuration combined with excessive chamfer from the factory left very little ring support on my cylinders.
Doing the top end is fairly easy but in would be nice to have a second set of hands during monoblock installation. Bleeding the system is as simple as blocking up the front of the sled so the motor is higher than the heat exchangers and burbing it twice.

Couple of things; The pistons in my kit had a steeper crown (1 and a bit degrees) so stick with stock head or talk to MNTKT if that is in your plans.

I purchased my kit based on answers and experiences I got from phone calls. You should too IMO. Especially if you feel you might farm out the installation. Pick someone who has done a few. Things like deglaze, break-in, ring sizing are all just as important a not forgetting the piston pin c-clip lol. The tech or shop with more experience is a better pick no matter which kit they are using.

Don't be afraid of stock. Many top shops still recommend and use stock. Most of these shops are rebuilders not parts installers. After I took mine apart I think I saw why. Just remember the recommended mileage intervals. What you or your tech find (make sure they provide you this too, proves they are rebuilding not just replacing) when you take yours apart will tell you what you need to know for your intervals.
It has to make you think when you read about high milers but it might not pertain to your sled anyway. For instance My sled is the smoothest running twin I have ever had in a sled. But some vibrate from the get go.

Durability lol. IMO real information between the kits is not out there. Info like before and after measurements after x # of miles is real hard to find. Either techs and shops don't keep a journal or don't care to share. On the 'net anyway.
My phone calls showed the Mntkt kit to be out the longest and used the most with good results. Not measurements but comfort in #'s. That was my reason for pre-purchasing that kit.

Hope it helps lol but you are asking a very often asked question with a very un answered history

geo I disagree strongly with you the stock pistons and rings are terrible. I pulled apart my 11 pro with 600 miles on it and the rings were badly flaking, install a rkt drop in kit and ran it for another year, removed the kit inspected the pistons and rings an found no discernible wear and no ring damage. with the same porting, also if you don't replace the pistons they will damage your cylinder skirts. ask boondocker155 about the skirt issue his engine was well maintained and the skirt cracked with less than 65 hrs on it! I recommend either the mountaintech kit or the rkt drop in kit or stock replacement pistons. I run them from day one in all my sleds. once again the stock pistons are a disaster and no good shop would use them in a stock motor. imo
 
R

rmscustom

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Jun 8, 2010
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My 13 pistons weren't that bad either (1300 miles). When I told Kelsey my clearance he thought they must of been flatland miles until I told him how much and which oil I used. My rings were another story, badly flaked and had major power loss by the end of last year... Rethought my Motoman break in procedure. lol
 

Powderforlife907

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Dec 14, 2011
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My 13 pistons weren't that bad either (1300 miles). When I told Kelsey my clearance he thought they must of been flatland miles until I told him how much and which oil I used. My rings were another story, badly flaked and had major power loss by the end of last year... Rethought my Motoman break in procedure. lol

I have yet to open my sled but I have definitely felt a loss in power at 1100 miles. Debating whether to go with Bikemans, or MTNKT right now...
 

freak485

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Feb 4, 2011
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Billings, MT
Wiseco pistons, got mine from Boston racing 330 bucks shipped with all the gaskets. This forum is full of wisecos whinners but they have more after market pistons out there with more hours/miles of anyone else. Thats why the best Fix kit...mtntk uses them. I am not a fan of having to use 2 base gaskets so i just replaced the stock pistons. I saw less vibration and a little bit quicker revs with the wisecos. About 800-1000k miles on mine wiescos all turbo at 9#. Go with the mtntk or just the kit like i did.
 

RanOutofTalent

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Dec 20, 2014
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Western Montana
I have a 14 pro 800 with 900 miles. I believe about 500 were flat land from the impression I got from the previous owner. I want to take the best possible care of this machine. What should I be looking for in regards to a motor with this amount of miles? I was thinking of riding this season and then putting the BMP Durability Kit in it. I am running Legend ZX-2SR oil. (I live close to the manufacturer and hear is a great product). Should I be taking the motor apart or is simply doing a compression test all that is necessary? Any and all advice is greatly appreciated.
 

tuneman

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I have a 14 pro 800 with 900 miles. I believe about 500 were flat land from the impression I got from the previous owner. I want to take the best possible care of this machine. What should I be looking for in regards to a motor with this amount of miles? I was thinking of riding this season and then putting the BMP Durability Kit in it. I am running Legend ZX-2SR oil. (I live close to the manufacturer and hear is a great product). Should I be taking the motor apart or is simply doing a compression test all that is necessary? Any and all advice is greatly appreciated.

If you research it enough, as I have, you'll find the Polaris 800 engine issues are over-hyped a bit. MY '13 and newer are pretty solid engines. If you haven't already, you'll want to get an improved oil cap. Then check your oil usage. If you're less than 50:1, turn up your oiler until you get there. Other than that, just ride it and enjoy it. Do a compression check a couple times a year (should be about 120psi). If you give your 2014 engine enough oil, it'll go for 5-6k miles, easily, before you need new pistons.
 

RanOutofTalent

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If you research it enough, as I have, you'll find the Polaris 800 engine issues are over-hyped a bit. MY '13 and newer are pretty solid engines. If you haven't already, you'll want to get an improved oil cap. Then check your oil usage. If you're less than 50:1, turn up your oiler until you get there. Other than that, just ride it and enjoy it. Do a compression check a couple times a year (should be about 120psi). If you give your 2014 engine enough oil, it'll go for 5-6k miles, easily, before you need new pistons.


Thank you. This makes sense. I have considered turning up then oil pump screw but have not checked the ratio it uses yet. I feel dumb for asking but what is the best way to do this?
 

tuneman

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There are no dumb questions, just dumb people that don't ask questions.

Start with a full tank of gas and mark the level of your oil tank with a Sharpie. Burn a tank of gas and refill to get gas consumed. Then refill oil bottle to the mark using a measuring cup to get oil used.
 
L
Nov 13, 2012
66
15
8
Waverly, MN
No one has mentioned IndyDans top end rebuild using OEM pistons and his honing on OEM cylinders to spec? Has anyone used this kit? I am really leaning this route planning on keeping it 3 more years and it only has 1300 miles on my '13 was rebuilt at 57 miles when it broke a skirt obviousley it's a bit more expensive than the other kits but his work is very quality from what I understand
 
L
Jan 29, 2010
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No one has mentioned IndyDans top end rebuild using OEM pistons and his honing on OEM cylinders to spec? Has anyone used this kit? I am really leaning this route planning on keeping it 3 more years and it only has 1300 miles on my '13 was rebuilt at 57 miles when it broke a skirt obviousley it's a bit more expensive than the other kits but his work is very quality from what I understand


A bit more expensive? you damn near need a 2nd job or another mortgage to pay for the indy dan setup
 

Norway

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Everyone needs to HEAR what geo said..

Measurements! I've replaced my pistons to, got new 2013 pistons for $100 so kind of no choice. But I admitted to my own limits and sent Fastrax my cylinders and old pistons. Said nothing was wrong with them and gave me the clearance.

The production of pistons and cylinders is not THAT acurate.. Giving some people a good clearance and some to big. Oil usage also varies, according to people reporting here.

Nervous or feeling powerloss = teardown and chack. Don't install new pistons, whatever brand, to get the same crappy clearance you had with your old ones.

Also, 2015 had new and better pistons while 2013 got thicker cylinder skirts. It all matters. Personally I'm in the market for some new takeoff 2015 pistons.

If you do it, do it right. Luck!

RS
 
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BILTIT

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Apr 9, 2011
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No one has mentioned IndyDans top end rebuild using OEM pistons and his honing on OEM cylinders to spec? Has anyone used this kit? I am really leaning this route planning on keeping it 3 more years and it only has 1300 miles on my '13 was rebuilt at 57 miles when it broke a skirt obviousley it's a bit more expensive than the other kits but his work is very quality from what I understand

I have an indy dan long rod engine, just installed his new HG7 finish cyl and new pistons. It is a tight fitting setup (no rock or piston movement at TDC like every other poo engine i have seen).

I am not sure if he sells just a top end but if he does i would go that way. The new cyl finish is amazing compared to the old style.
 
L
Nov 13, 2012
66
15
8
Waverly, MN
I have an indy dan long rod engine, just installed his new HG7 finish cyl and new pistons. It is a tight fitting setup (no rock or piston movement at TDC like every other poo engine i have seen).

I am not sure if he sells just a top end but if he does i would go that way. The new cyl finish is amazing compared to the old style.

Yeah he sells a kit with new jugs and pistons then spec'd ang HG7 finished just wondered if anyone else tried it I know you get what you pay for so that's prolly why it's $1200
 

BILTIT

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Apr 9, 2011
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I rode it in the mountains 1.5weeks ago. First ride of the year so couldn't say much about it versus his old setup.

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X

xc6rider

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Jan 12, 2009
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I sent cylinder to Indy Spec for the HG7 hone and new Pistons, it was nowhere near $1200. Under $450 with ProX pistons and gaskets, shipped. OEM pistons would have been about $250 more.
 

rags319

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Yeah he sells a kit with new jugs and pistons then spec'd ang HG7 finished just wondered if anyone else tried it I know you get what you pay for so that's prolly why it's $1200

It's $1200 but you get $500 back for a core charge if I'm seeing it right. $250 less for pro x pistons. 3 year warranty on lower sleeve breakage. Tough to beat that I think. Check it out on his eBay store
 

rags319

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It's $1200 but you get $500 back for a core charge if I'm seeing it right. $250 less for pro x pistons. 3 year warranty on lower sleeve breakage. Tough to beat that I think. Check it out on his eBay store

Sorry guys I was wrong. Called him today. It is $1200 with oem that's if he has your cylinder. EBay was little misleading too me.
 
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