• Don't miss out on all the fun! Register on our forums to post and have added features! Membership levels include a FREE membership tier.

Well shucks.... Melted another piston

C
Feb 23, 2017
20
15
3
2016 RMK 800, had a super high idle (4000 rpms) issue at the end of spring 2020 that turned out to be a bad crank bearing and seal and a bad piston. Took it to the most reputable shop in town (Darby's in Fairbanks) and had them do a total rebuild, new crank and all. Cost me $3300. Put about 300 problem free miles on it last season.

Finally got it out for the first rides of the season over the Christmas weekend, had two good days, then on Christmas day it died and locked up about 15 minutes into the ride. After about 5 minutes it was willing to turn over, fired up and sounded fine, but very shortly after dropped to one cylinder. Limped it back to the house and it was rattling something fierce by the time I got there.

Pulled the head off and it's the same piston that melted last time. Cylinder has some pretty gnarly gouges and the head is toast as well.

Sled has just over 2800 miles on it, and it's in decent shape overall. Probably 1-2 seasons from needing a new track, and after rebuilding the clutch last year, I'm already thinking I should have just bought a new clutch.

Considering options, 1) Rebuild it again and keep it. 2) Rebuild it and sell it right away and save the money for a snow check in the spring. 3) Try and sell it as is, and snow check in the spring. Thoughts / opinions?

Thanks
 

Sheetmetalfab

Well-known member
Lifetime Membership
Oct 5, 2010
7,892
6,607
113
……..
2016 RMK 800, had a super high idle (4000 rpms) issue at the end of spring 2020 that turned out to be a bad crank bearing and seal and a bad piston. Took it to the most reputable shop in town (Darby's in Fairbanks) and had them do a total rebuild, new crank and all. Cost me $3300. Put about 300 problem free miles on it last season.

Finally got it out for the first rides of the season over the Christmas weekend, had two good days, then on Christmas day it died and locked up about 15 minutes into the ride. After about 5 minutes it was willing to turn over, fired up and sounded fine, but very shortly after dropped to one cylinder. Limped it back to the house and it was rattling something fierce by the time I got there.

Pulled the head off and it's the same piston that melted last time. Cylinder has some pretty gnarly gouges and the head is toast as well.

Sled has just over 2800 miles on it, and it's in decent shape overall. Probably 1-2 seasons from needing a new track, and after rebuilding the clutch last year, I'm already thinking I should have just bought a new clutch.

Considering options, 1) Rebuild it again and keep it. 2) Rebuild it and sell it right away and save the money for a snow check in the spring. 3) Try and sell it as is, and snow check in the spring. Thoughts / opinions?

Thanks
You would get ok money for it as is i bet. 3-3500.

There’s something wrong that wasn’t caught the last rebuild.

Injector?
Bubble in oil line?
Water ingestion?

I’m 100% in the sell it as is camp.
 
C
Feb 23, 2017
20
15
3
That's the way I'm leaning right now. My buddies are trying to talk me into rebuilding it so I can ride the rest of the season, but I'm just not sure. Something is definitely wrong with it, I'm not sure what, and I'm working waaaay too much to have time to wrench on it. I'm into it far enough money wise I'm ready to walk away and start fresh.

If I sell it as is, then my conscience will be totally fine, no sellers remorse about unloading my problems to some other poor sucker.

Sucks there's really not much used for sale right now, and last time I was at the dealer they didn't have squat. And we just got the dump of a lifetime and I can't go ride.

Thanks for the input
 

Sheetmetalfab

Well-known member
Lifetime Membership
Oct 5, 2010
7,892
6,607
113
……..
That's the way I'm leaning right now. My buddies are trying to talk me into rebuilding it so I can ride the rest of the season, but I'm just not sure. Something is definitely wrong with it, I'm not sure what, and I'm working waaaay too much to have time to wrench on it. I'm into it far enough money wise I'm ready to walk away and start fresh.

If I sell it as is, then my conscience will be totally fine, no sellers remorse about unloading my problems to some other poor sucker.

Sucks there's really not much used for sale right now, and last time I was at the dealer they didn't have squat. And we just got the dump of a lifetime and I can't go ride.

Thanks for the input
I’m currently without a sled also waiting on my snow-check boost.

Hoping it shows so I can hit that dump of snow you are talking about. :)
 
C
Feb 23, 2017
20
15
3
I did post it on craigslist last night, and have three people currently biting on it, we'll see if something works out. It'd be great to just walk away, but that probably means taking a year off from riding. O-well, is what it is.

It's been snowing hard core up here. I'm in Healy and we've gotten pushing 3 feet over the last week or so. Sucks it rained about 2" the day after Christmas and flattened it out a bunch, but we got about a foot of primo fluffy powder after that and things are looking good. The wife is a dog musher and was down on the Denali Hwy two days ago and said it's easy waist deep, and super soft. Sounds like Cantwell escaped the rain. Can't imagine what it's like a little further south and up in the mountains.

Good luck with the sled delivery! Besides the boost, which model did you order?
 

powdrdaz

Well-known member
Lifetime Membership
Jan 15, 2012
162
48
28
you can always rent
Cheaper then fixing it. Unless you will be riding more then 10 times
 
C
Feb 23, 2017
20
15
3
That's an interesting thought. There is a Polaris dealer in town, but I don't believe they do any rentals. Never seen / heard of it anyway, but that would be a perfect solution for the rest of the season. If I drive across the state to some other riding areas, it would take me through Fairbanks, and I do believe there's some rental possibilities up there, but I've not looked into it
 

Sheetmetalfab

Well-known member
Lifetime Membership
Oct 5, 2010
7,892
6,607
113
……..
That's an interesting thought. There is a Polaris dealer in town, but I don't believe they do any rentals. Never seen / heard of it anyway, but that would be a perfect solution for the rest of the season. If I drive across the state to some other riding areas, it would take me through Fairbanks, and I do believe there's some rental possibilities up there, but I've not looked into it
Rent from aksledjunkie in wasilla.
 
C
Feb 23, 2017
20
15
3
I have heard of that guy, but haven't ever ridden south of the Chulitna area. I've got some buddies in fairbanks and have driven all the way over to Summit to ride with them before. Wouldn't mind getting down south to ride some time, and I'll keep that guy in mind.

MIGHT sell the sled tomorrow, guy seems pretty locked in on taking it home. Fingers crossed
 
M

MATTELL

Member
Oct 25, 2012
13
6
3
2016 RMK 800, had a super high idle (4000 rpms) issue at the end of spring 2020 that turned out to be a bad crank bearing and seal and a bad piston. Took it to the most reputable shop in town (Darby's in Fairbanks) and had them do a total rebuild, new crank and all. Cost me $3300. Put about 300 problem free miles on it last season.

Finally got it out for the first rides of the season over the Christmas weekend, had two good days, then on Christmas day it died and locked up about 15 minutes into the ride. After about 5 minutes it was willing to turn over, fired up and sounded fine, but very shortly after dropped to one cylinder. Limped it back to the house and it was rattling something fierce by the time I got there.

Pulled the head off and it's the same piston that melted last time. Cylinder has some pretty gnarly gouges and the head is toast as well.

Sled has just over 2800 miles on it, and it's in decent shape overall. Probably 1-2 seasons from needing a new track, and after rebuilding the clutch last year, I'm already thinking I should have just bought a new clutch.

Considering options, 1) Rebuild it again and keep it. 2) Rebuild it and sell it right away and save the money for a snow check in the spring. 3) Try and sell it as is, and snow check in the spring. Thoughts / opinions?

Thanks
What do you want for it? Where are you located?
 
C
Feb 23, 2017
20
15
3
Sold it! And got a pretty fair price for it. Sure hope it works out for the guy, it felt awful weird selling a down machine. Hope I didn't sell him a problem child.

Can't freakin believe it but the local dealer had ONE machine on hand, a '22 RMK 850 with a 155 track. Let the season resume. Thanks for the advice Sheetmetalfab!

new sled.jpg
 
Premium Features