Pro 800 Motor Failures

[oldym8rider]

Keep hearing that no matter what year of Pro 800 motor you get get there seems to be a pretty high failure rate on these motors at around the 1400km - 1800km mark. Is this true or just a bunch of crap? if it's true what seems to be the problem and what's the fix for the issue or issues? Thanks for any and all replies.

 

[SwervinMervin]

Mine blew up at around 1200 miles. I suspect it was under oiling. I think that if you crank up the oiler just a bit or maybe add a little oil to your tank each fill you would be way better off.

I also think that the engine itself is not any less reliable then the other manufacturers.

 

[Bnorth]

They seem to be getting better the newer they are. Issue is generally piston skirts collapsing and then breaking off. Numerous fixes including RK-tek pistons, Indy Dan long rod motor, or the "fix kit" from MTNTK. They're probably slightly less reliable than an 800r doo motor and they rarely last as long as a Cat 800 or Etec 800.

 

[prairie-rider800]

I've got 1400 trouble free miles on my 13 pro 800. I add some oil to the gas and so far it's been great! But I think am going to put a new set of pistons this summer just for preventative measures.


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[oldy800]

Hey thanks for the posts guys, keep em comin, just wonder why in this day and age reliability in a sled that costs 12000 - 14000 dollars is so piss poor? Np matter what manufacturer is building it. Yes ive heard good things about the Indy Dan fix, but its basically a total overhaul of the motor, makes very lil sense to be doing this to a motor that is running but ready to grenade

 

[ABMax24]

Replaced pistons on my 13 at 1200km due to excessive clearance, had the inlet fitting pull out of the oil pump at 2500km would have ruined the motor but noticed the puddle of oil under it so got towed home.

 

[Vance Matheson]

Replaced pistons on my 13 at 1200km due to excessive clearance, had the inlet fitting pull out of the oil pump at 2500km would have ruined the motor but noticed the puddle of oil under it so got towed home.

The fitting on the bottom of the oil pump came out of mine/my sonns also and it cooked the top end.

 

[JMCX]

2000 mountain miles on my '13. No problems. It's not the piston but cylinder skirts that break on the pre '13 engines. They did some tweaks for '13 and you don't hear about it much any more.

 

[ABMax24]

2000 mountain miles on my '13. No problems. It's not the piston but cylinder skirts that break on the pre '13 engines. They did some tweaks for '13 and you don't hear about it much any more.

The cylinder skirts break because of piston slap due to excessive clearance, so to fix the issue they made the cylinder skirt thicker instead of getting a quality piston. Check the pistons on your 13, I'm sure you will find the pistons have shrunk.

 

[TKrebs]

Had 2900 miles on my Pro with an aftermarket head. Always added a little oil. Still had 120 per cylinder when i sold it.

 

[snowho]

I have 1600 miles on my 2012 and it blew mid march. I loaded it up with extended warranty and it's still being worked on. The last time I heard the motor is somewhere in Quebec don't even know if I'll get her back buy September. Not to sure if I would buy another RMK even current model year and certainly would not deal with cycle works anywhere. They said the fix kit makes it worse. I don't believe this at all when I get it back, if I keep it, I'll put the kit in myself. Not to sure what happened all I know for sure is there was a hole in the crank case the size of a quarter with small chunks of the piston laying in the tub.

 

[ABMax24]

I have 1600 miles on my 2012 and it blew mid march. I loaded it up with extended warranty and it's still being worked on. The last time I heard the motor is somewhere in Quebec don't even know if I'll get her back buy September. Not to sure if I would buy another RMK even current model year and certainly would not deal with cycle works anywhere. They said the fix kit makes it worse. I don't believe this at all when I get it back, if I keep it, I'll put the kit in myself. Not to sure what happened all I know for sure is there was a hole in the crank case the size of a quarter with small chunks of the piston in the laying in the tub.

Crappy deal. I have the MTNTek fix kit in mine and it seems to work well, I now have ~1200kms on the pistons with boost and they still look good and will be ran for another season, I would definitely recommend a fix kit over stock pistons.

 

[OnlyPolaris]

We have 3 Pro's in our stable and haven't had any engine issues. The only thing I can say is that from brand new we turn up the oil pump. One 2011 with right around 2000km, One 2013 with around 1200km and the other 2013 has arouns 700km.

 

[CamoKVF700]

Boost is your friend on these motors with stock Pistons. Boost keeps the Pistons true in their bore. If all these blown motors had a turbo installed from new they'd all still be running.

Sent while wishing I was on my snowbike

 

[rmscustom]

Boost is your friend on these motors with stock Pistons. Boost keeps the Pistons true in their bore. If all these blown motors had a turbo installed from new they'd all still be running.

Sent while wishing I was on my snowbike

Why do you think that is??? More fuel than the lean stock map is my theory... I think a fuel box and turning the oiler up on these sleds is the real fix kit.

 

[Vance Matheson]

Why do you think that is??? More fuel than the lean stock map is my theory... I think a fuel box and turning the oiler up on these sleds is the real fix kit.

extra fuel wont stop the piston slap but boost works but so does the fix kit pistons

 

[rmscustom]

extra fuel wont stop the piston slap but boost works but so does the fix kit pistons

Maybe a cooler running motor (extra fuel) keeps the skirts from collapsing.

 

[CamoKVF700]

Boost keeps these inferior Pistons true in their bore.

A perfect tune helps of course.

Sent while wishing I was on my snowbike

 

[Vance Matheson]

Maybe a cooler running motor (extra fuel) keeps the skirts from collapsing.

you have a good point, and it mostly makes a difference but a sloppy piston is still a sloppy piston hot or cold.

 

[ABMax24]

I personally believe it is heat cycles that collapse the pistons, the more times they go from hot to cold the more they collapse, but that's just my theory.