Got boost want snow
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Had an 850 with 4000km blow up on the weekend. Or it had to be towed home went extremely stiff on on cylinder.
Why DOO SKI-DOO motors blow up at such a low mileage?
- Thread starter Longhairfreak
- Start date
Luke The Drifter
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So if these 850s aren’t getting the same mileage compared to a 800 etec. What’s the reason? Is it lower quality materials? Different tolerances? Nature of the beast’s design? Both are great engines IMO, I spent a couple days the other week in revy on a 2020 NA 850 and a 2022 turbo freeride. I still can’t get over at how much more snappy they are compared to the etec I had in my 2015 T3. Plus having SHOT was great too.
bendy
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Yeah… people are nuts. We were out on the weekend. Roads were dry but you could literally see the white powder from the road salt kicking up from the vehicle in front of me!
maxwell
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Exactly and
Exactly! OEM oil, good premium fuel and proper warm ups. How many guys stop for 15 minutes or more then start it up and hammer on it. Engine temperature is still up but when the thermostat opens and the cold coolant from the tunnel hits then things go boom. I always watch the temp gauge until I see the thermostat open then wait for coolant to cycle and warm up.
greenthumb
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Completely agree.
"Cold sizing" was an issue on some old Polaris', just as you describe. Sudden rush of cold coolant shrinks the jugs to the point there was no clearance left with warm pistons. E-tec's run a bypass hose that recirculates some of the hot coolant back with the cold to mitigate this. Also keeps coolant temperatures more consistent throughout the engine, but you can still do it by hammering down on a cold engine. By no means new technology; pretty much every automotive engine does this too.
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greenthumb
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Many of the 850 failures I hear about, including my own are piston skirt failure. I'll bet all these sleds that are over-revving out of the box doesn't help.
I still think warranty is a factor here. When you have a 3 or 4 year unlimited mileage warranty and high parts cost, there's no incentive to do preventive maintenance like people did years ago. Just run it till she blows, get a new engine, and sell while it's at a high resale value. Some of the failures may have had some "help" just before the warranty expires.
I remember not so long ago when Polaris had one year warranties and people were changing pistons on brand new sleds to increase engine longevity
maxwell
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Yup! It’s interesting. If you go into the cabin for a break and come out 30 mins later. Fire up your sled and it will read above 30 degrees which is ok to start moving. But if you let it sit and keep circulating coolant you will start to see those numbers drop to the point that it would be in warmup mode if it was a fresh cold start. My sled doesn’t move until the temps are climbing past 30c. That’s morning, off the deck, out of the trailer, after leaving the cabin. Anywhere any time
sledneck__11
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How many guys fire up there sled cold off the deck frozen down and romp
On it to get it unstuck,unloaded,that rasp of a cold sled is pretty easy to notice. rode our local rally this weekend rode with a couple
800 and 1000cc triples before we left any where they would go start there sleds let them warm up 10 mins before they left lol
On it to get it unstuck,unloaded,that rasp of a cold sled is pretty easy to notice. rode our local rally this weekend rode with a couple
800 and 1000cc triples before we left any where they would go start there sleds let them warm up 10 mins before they left lol
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The early 850's seem to have an issue with the mag side piston skirt. May have one more with this issue.
SUMMIT TREE
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Yeah. I agree. My sleds don’t move until the cooler is warm and its out of warm up mode. See tons of guys fire up and immediately move the machine. And the no tarps thing! Wtf?? Seen two newer summits on an open trailer 2 weeks ago that literally looked like they spent the weekend at mudfest! They were covered in Nasty brown schmoo, so nasty. Spend 18K or more on a sled and then don’t buy a 200 dollar tarp. 
sledneck__11
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They still get bad enough with the tarp on, had a deck for 2 seasons went back to enclosed trailer due to ocd issues lolYeah. I agree. My sleds don’t move until the cooler is warm and its out of warm up mode. See tons of guys fire up and immediately move the machine. And the no tarps thing! Wtf?? Seen two newer summits on an open trailer 2 weeks ago that literally looked like they spent the weekend at mudfest! They were covered in Nasty brown schmoo, so nasty. Spend 18K or more on a sled and then don’t buy a 200 dollar tarp.
SUMMIT TREE
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Yeah I know. I was always gonna spray my tarp down with Neverwet, but never got around to it.
Covers don't keep the salt laden moisture out especially on a trailer. Way less crap when up on a deck but it's still there ..
Little bit of prevention helps too.... dielectric grease on all connections and liberal use of fluid film or similar helps. Thorough clean before storage. Clean fuel. Proper warm up. All help ensure best possible life.
Rest is luck!
Little bit of prevention helps too.... dielectric grease on all connections and liberal use of fluid film or similar helps. Thorough clean before storage. Clean fuel. Proper warm up. All help ensure best possible life.
Rest is luck!
kingcat162
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From real world experience there bud - 800 etec is one of the toughest motors on the planet I've been proving it for 8000kms
maxwell
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I’d have to take off a sock
To count how many times your sled has blown up so
I’m not sure what your talking about
kingcat162
Active VIP Member
That's funny - I put a top end in it this season other than that - any other motor work has been voluntary
Good to see many people observing how important proper warm up is. In addition, lots of these issues are related to emissions. The oil injections are cranked down on all OEM motors to meet the emissions standards, and they don't want to crank them back up after for the production stuff - nobody wants to be the next Volkswankin' where they meet the targets at the test and then fail in the real world.
I've been watching these engines for years, and primarily the way they inject the fuel and oil separately plays a big part in motor longevity. The case oil injection only does so much to pick up the oil in the intake charge as it comes through. The top down fuel injection then also washes some of the oil from the cyliinder and the RAVE injectors. Not enough lube is getting to the bottom portion of the piston. The skirt wears and it either rocks in the cylinder until it breaks off or it loses compression. The Doo has a pretty low rod ratio so that contributes to the skirts breaking in any engine typically. This is not a Ski Doo bash, just an observation, all OEM's have similar issues.
Good preventative maintenance and never hurts to dump 2-3 capfuls of oil into a each tank of fuel (or a bit more) - just gives it a little more lube in the top end from the injector side. Change plugs 2-3 times a season is still cheaper than a top end.
I've been watching these engines for years, and primarily the way they inject the fuel and oil separately plays a big part in motor longevity. The case oil injection only does so much to pick up the oil in the intake charge as it comes through. The top down fuel injection then also washes some of the oil from the cyliinder and the RAVE injectors. Not enough lube is getting to the bottom portion of the piston. The skirt wears and it either rocks in the cylinder until it breaks off or it loses compression. The Doo has a pretty low rod ratio so that contributes to the skirts breaking in any engine typically. This is not a Ski Doo bash, just an observation, all OEM's have similar issues.
Good preventative maintenance and never hurts to dump 2-3 capfuls of oil into a each tank of fuel (or a bit more) - just gives it a little more lube in the top end from the injector side. Change plugs 2-3 times a season is still cheaper than a top end.
kingcat162
Active VIP Member
Or put an aftermarket turbo on it and that hoor will spit all the extra oil in the intake that's necessary
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