Nytro engine issue. Did I blow it up?

[cawcislo]

Well here's the story. Went for a ride, nytro was getting real hot, light was blinking so I pulled over, looks like it overheated as a little coolant came out the overflow from the bottle. Let the sled cool down, fired it back up, engine didn't sound right, thought it sounded like a knock maybe. 1/2 mile later heard a pop/bang and the engine died. Starter sounds like it still rotates the motor over, but won't fire. Hmmm. Fun stuff. P.S. No warranty, even better. I wonder if I should do a compression test first.

 

[cawcislo]

Update....sled cooled off for a bunch of hours and I just tried to fire it up. It fires for 2 seconds and then stalls, so now I'm thinking spun a rod bearing.

 

[nytrose]

what kind of conditions you riding in up there?

 

[gems4sale]

I think the Nytro has two levels of warnings for over heating. It glows yellow at first then goes green. I think it starts detonating after it turns green. Mine did the first ride out. You may have scuffed a piston if you didn't notice the light on. When you shut off a hot motor it goes hotter at first with no coolant flow. It wouldn't be good to try restarting it after 2 minutes. I use synthetic Ams Oil which I think helps with hot motors. Hopefully it isn't anything much. Your motor should be fine as it should detonate if it gets too hot. Hope it much...

 

[grizztracks]

I'd start with a compression test. Most engine heat comes from the cylinders so overheating normally damages the upper end first (rod, piston, valves). A spun rod bearing shouldn't keep it from running but if you had upper engine damage like a blown piston all the pieces fall to the lower end causing additional lower end damage. It sounds like its not detecting oil pressure in the first few seconds so its shutting down. All it takes is a small piece of debris to block an oil port or damage the oil pump. If you heard a knock you should have stopped running it. My guess is that there's serious damage and a good chance the engine is beyond repair.

This is the first actual "overheating" Nytro I've heard of. I've expressed my concerns about running hot and I posted an overheating poll several weeks ago which shown about 50% of the Nytro's having overheating issues. I'll be installing a tunnel heat exchanger before next season.

 

[cawcislo]

Guess I don't have to worry about doing that compression test.

 

[cawcislo]

Riding conditions. It was -4, theres probably 2-3 feet or hard packed snow on the trail. When the sled got hot and overheated I let it cool for like 15-20 minutes. It sounded like it had a knock when it fired up again and I drove it for like 2 minutes and then boom.

 

[EsonPZ]

Talk to your dealer. From what i have heard Yamaha is known for godwill on enginetrouble. It might be worth trying.

 

[scott32]

I hope you have a good relationship with your dealer because this website is like a journal for the dealers to see what your doing to the sleds. Why does everybody want their mistakes covered by warranty?

 

[Crewchief47]

Contact your dealer. As was mentioned, Yamaha appears to be 'taking care' of some motor issues after investigating. I would doubt the overheat caused a cap issue, more likely the cap issue caused the overheat, assuming the oil system is full and functioning.

 

[cawcislo]

What's I don't understand is that there's a rod bolt sitting on my bellpan. It's not broken, mangled twisted or anything. It's like it wasn't even tightened and it came undone. Oil system worked fine. It had enough oil and the oil was clean. As for the contacting your dealer. I bought this sled in the US and now it's in Canada. Which dealer do I contact? My local dealer?

 

[SledFreak]

You have to go back to the states... What I would do is call the U.S. dealer and then call U.S. Customer service and tell them what happened. Don't bother calling Canada, as they will nothing.

 

[Csellors]

My motor blew up after a lake run at approx 85-8900 rpm's. It threw a rod and damaged all the cases. No warning lights, after i started to decellerate it just stalled and you could tell immediately that something was wrong. Pretty embarrasing being towed by a doo 20 miles. The motor is junk now. No warranty and i have been to Yamaha and they will not cover it. My dealer is great by the way, they have really fought tooth and nail with Yamaha, but no go. So much for Yamaha quality. I was quoted $6800 for a new motor which is absolutely ridiculous. I have been looking in the U.S for a wrecked Nytro with a good motor. I bought a four stroke so i wouldn't have to deal with motor issues, funny thing is, i never had any motor issues with my doo's. Good job with this one Yamaha.

 

[MNUser]

What is that sticking out the bottom of the engine? Did a bearing go to cause it to be off center and break out the casting? How many miles on the sled?

 

[arteeex]

I don't see a problem. A little work with some buffing compund and you'll up and running in no time.

Other than the blinking warning light there was no other indication that your motor was about to grenade?

How many miles/km were on this motor?