Blown Top End in 2014 Pro- What to do next and options?

JustChilling19

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Hi All,

Blew out one of my pistons in Revy this weekend. It was deep!! If your standing on the sled it would be the left side piston. Happened on the trail. The sled just shut off going about 60km/h. Went to pull the rope and there was a ton of resistance. Once you fully pulled the rope and let it recoil it would go back to normal. Started it using the throttle and rode another km or two when the sled started losing rpm from 6500 down and then turned itself off again. At this point we decided to just tow it the rest of the way.

Did a compression test last night and the right cylinder is getting 110 (same all season). Left is getting absolutely nothing on the gauge hence why I now know I blew the piston. One plug is orange (left) and one is grey (right).

Havent ever blown a top end up before so this is all new to me. What suggestions do you have to do next? What do I got to do and look out for? Any recommendations are appreciated. The only blessing here is that there is not a lot of snow called for over the next two weeks.

Cheers,
Tyler
 

BILTIT

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Talk to Dan at Indy specialties (mountain magic in edmonton is their dealer here in canada i believe). He will fix you up with the latest in cyl finish and engine reliability all with a 3yr warranty. He stands by his warranty.
 
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Tchetek

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Open it up and see what the damage looks like and if there material that may be down in the crank. Once it’s open try to determine what caused it to fail from the evidence.

Motts machining in edmonton likely has a cylinder block in stock they will exchange if yours is damaged.

Then install new pistons or a fix kit.
 

shell_guy

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Pull it apart, check cylinder for damage, marks are fine, if you can catch your finger nail in a scratch it will need to be re-coated. Skylark Machining is the beat for repair/recoating in Calgary 403-807-8747 is his number.

If the cylinder is fine then put new pistons, rings, and rod bearings in and go! Its not a big job, pull the steering arm, over structure, and pipe, then you can pull the head an cylinder.
 

JustChilling19

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Hey Everyone,

Thanks for the replies. Sounds like I have to get the courage up and crack into this thing myself. Any tips? What is the best way to drain the antifreeze? Anything else to look out for when simply taking it apart?

As for re-honing/re-machining I am getting conflicting information. Half is saying I will ‘need a new cylinder’ others are saying I can rehone and some saying could also rebore (both). Obviously it would be preferential to reuse the cylinder if I can. Guess I will keep everyone updated.

The machine had about 3000kms on it. All mountain and all hard in some pretty deep snow conditions. This past Sunday in Revy was nuts. Over 2 minutes to the bar to pull AB hill. In your face powder carvs coming down haha I’m actually pretty impressed at how well this machine held together for this long. No signs leading up to it either.

Appreciate the suggestions!

Cheers,
Tyler
 

shell_guy

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When you take the sled apart, have a good look at the cylinder, if there are no marks that you can catch a finger nail then your good to go and reassemble. The cylinder is nikisyl coated, you can not hone a nykisil coated cylinder with a standard hone like you could in the old days. Once you get it apart, call Skylark Machine, they will inspect the cylinder, hone with a diamond hone, or re-coat if required.
 

Tchetek

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Be brave, it’s pretty easy. Just bag all the small parts in baggy with a note referring to locations as you disassemble. You won’t know about the cylinder till you open it up. If it looks good take it to a shop for measurements and a hone. If it’s fawked swap it for a refurbished. Just Hope all the pieces are still together Inside so there isn’t bullshat down on the crank.


Mine ran perfect, Compression never changed from when I got it. Reluctantly Decided to do a top end at 1500 miles as preventative maintenance and the cylinders looked great but then I flipped it over and found the cylinder skirt cracked and ready to .

Motts machining was great for parts and advice for my first rebuild.

Measure and set ring end gap!

b42056e47d7b5316e2302655b18a863e.jpg
 

Jorg Jorgenson

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Be brave, it’s pretty easy. Just bag all the small parts in baggy with a note referring to locations as you disassemble. You won’t know about the cylinder till you open it up. If it looks good take it to a shop for measurements and a hone. If it’s fawked swap it for a refurbished. Just Hope all the pieces are still together Inside so there isn’t bullshat down on the crank.


Mine ran perfect, Compression never changed from when I got it. Reluctantly Decided to do a top end at 1500 miles as preventative maintenance and the cylinders looked great but then I flipped it over and found the cylinder skirt cracked and ready to .

Motts machining was great for parts and advice for my first rebuild.

Measure and set ring end gap!

//uploads.tapatalk-cdn.com/20180223/b42056e47d7b5316e2302655b18a863e.jpg

That's really good to know because my 13 Pro I bought with 370miles at the beginning of last season it now has just over 1900 miles. Same thing compression I check every couple rides, I'm religious with warm-up procedure, turned up oiler all that jazz (and I know I'm not as hard of a rider as some guys out there..) but this summer I'll for sure be doing a fix for peace of mind. And for that exact reason like you found!

Jorgy did his last summer and also had a great experience at Motts. My only word of advice is don't try to do the ring gap on your own.. take it to someone with the new pistons so they can accurately size em up to each piston. Someone else's experience that I witnessed
 

Kyle89

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That's really good to know because my 13 Pro I bought with 370miles at the beginning of last season it now has just over 1900 miles. Same thing compression I check every couple rides, I'm religious with warm-up procedure, turned up oiler all that jazz (and I know I'm not as hard of a rider as some guys out there..) but this summer I'll for sure be doing a fix for peace of mind. And for that exact reason like you found!

Jorgy did his last summer and also had a great experience at Motts. My only word of advice is don't try to do the ring gap on your own.. take it to someone with the new pistons so they can accurately size em up to each piston. Someone else's experience that I witnessed
Checking or changing ring gap you don't need an expert. Set of feeler guages and a file is all you need to get it to the spec you want
 

BILTIT

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And to add.. rings don't get the end gap sized to the piston, they get sized to the bore. The proper ring should come with the piston in all other size aspects.
 

Tchetek

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Checking or changing ring gap you don't need an expert. Set of feeler guages and a file is all you need to get it to the spec you want

Yea. Not rocket science. Pretty easy. YouTube will show ya if needed.
 

Audette13

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Hey Everyone,

Thanks for the replies. Sounds like I have to get the courage up and crack into this thing myself. Any tips? What is the best way to drain the antifreeze? Anything else to look out for when simply taking it apart?

As for re-honing/re-machining I am getting conflicting information. Half is saying I will ‘need a new cylinder’ others are saying I can rehone and some saying could also rebore (both). Obviously it would be preferential to reuse the cylinder if I can. Guess I will keep everyone updated.

The machine had about 3000kms on it. All mountain and all hard in some pretty deep snow conditions. This past Sunday in Revy was nuts. Over 2 minutes to the bar to pull AB hill. In your face powder carvs coming down haha I’m actually pretty impressed at how well this machine held together for this long. No signs leading up to it either.

Appreciate the suggestions!

Cheers,
Tyler


I just did this whole project on my 14 Pro a few weeks ago. My first time also. I lucked out and decided to do my top end before it let go (1975 miles). I purchased the MTNTK drop in kit (fix kit, head, timing key and exhaust valve springs). I wanted a little more jam with the reliability.

like everyone is saying, its easy, take your time, clean everything and ensure all wiring is ok while you are in there. Motts machining took care of my cylinder for me, $50 i think.

I replaced my reeds and they were chipped(went with boysen petals). Replaced a melted stator plug, ensure everything is secured and tight upon re assembly.

I also did my motor mounts, all new top end gaskets(some say to reuse some but i just replaced everything including injector o-rings). Service/clean exhaust valves, i replaced exhaust donut and springs as well.

Once completely rebuilt, i did 3 heat cycles on the engine and the pretty much just rode it normally (tried not to hold wide open for long periods but that didn't last too long lol). 32oz oil in the first tank (Polaris manual and MTNTK both specified this).
Ran strong for the first 3 rides, unfortunately I think I lost my VR yesterday as i lost my gauge.
 

Chrisco

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We have all the parts in stock if you need, give me a call if you have any questions. Thanks Chris.
 
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