Nytro engine broke rod????

[theflamanguy]

Last ride of the season the MCX oil return pump came off of mag side engine cover. I noticed oil on the snow after i stopped to investigate one of our cat riders sleds stopping. I dont know why it happened, but the threads on the engine cover were smoothed, i believe from vibration. prolly a loose pump. so i limped the sled to the nearest ditch running it at engagement rpm with the engine shutting down automatically every 30 yards or so. I got the sled in my garage and pulled the mag side engine cover and could not find the 3mm pin that drives the return pump. It was nowhere to be found and there was evidence that it had been bouncing around the mag. So I replaced the pin and engine cover, cleaned up the threads of the pump on a lathe and reinstalled. I also poured oil through the top engine fill to flush any unwanted debris that may have found its way into the engine. I finally got around to trying to start the engine the other day and after a few cranks and sputters, but not running, the engine tightened up! I couldn't turn it by hand. So, i left it for a couple days, then last night I removed the plugs and cranked it again. It was still tight and then something went "POP"! The engine turns free now by hand but every revolution there is a knock. Like something hitting the cylinder wall as you turn the clutch by hand. This only happened under battery power, there was no spark plugs in the engine when it went "pop".
I believe i have a spun bearing and a broke rod on Mag side. Does this sound familiar to anyone???
Anyways, the engine is coming out soon. Maybe an upgrade to 240 is in my future!!!

 

[mulot30th]

that sure is not .... funny. at least better happening now thant during winter.

 

[kinger]

You burned it up, you cant run the engine that long with no oil pressure, once it shut itself off you need to leave it and tow it, starting up again and again repeatly killed the engine.

Pull it out and see what is broke, my guess is all the rod and main bearings, and rings are shot.

 

[rxrider]

Cam shafts and bearing surfaces may also be damaged from lack of oil pressure.

Get a knowledgeable engine mechanic have a look at your motor, better yet have him do the disassembly of your engine.

 

[theflamanguy]

yep, gonna send it to B.C. My only other question is this, how much oil pressure could there be on the mag side? it only seems like besides magneto, the starter gear is on that side and cam chain. my best gestimate is that ther would not have been much pressure lost on the mag side???

 

[rxrider]

Impossible to know without running data logging on the oil pressure. Maybe your ECU has recorded something.... if my memory serves me... ask your dealer if they can download data from your ECU.

 

[nytrix]

Did the bolt on the oil return pump(magneto) loosen?

 

[rxrider]

If the oil pump is not correctly installed (too loose) it will vibrate loose, this will destroy the tiny cross bolt on the pump shaft.

 

[MOUNTY]

Impossible to know without running data logging on the oil pressure. Maybe your ECU has recorded something.... if my memory serves me... ask your dealer if they can download data from your ECU.

BAHAHAAHAHAHAHA!!!!!!! I know his dealer and there is no way, or anyone there that probably knows how to do it.

 

[towerrigger]

BAHAHAAHAHAHAHA!!!!!!! I know his dealer and there is no way, or anyone there that probably knows how to do it.

LOL!

 

[budman 1000]

Hey there Boost sorry to hear about your trouble; I had my oil return pump come loose aswell on my mcx turbo and I was a little more lucky as my buddy behind stopped me because of the blue smoke coming from my exhaust. with the return pump falling off the oil from the turbo has no where to go but past the seals into your exhaust and intake side of turbo, the engine still has oil pressure but you will pump your oil out through the turbo. When I took her apart my pump threads were gone and threads on end cover shot also; the oil pump drive cross pin was jammed in my stator and stator was also fried. The precooler had about half a litre of oil in it also; so I was getting a lot of oil into the cylinders also which could have caused a problem had i maybe kept driving; I did the fix myself and used loctite on the threads of the new pump; cost of the repair was just under 2000 dollars, very nasty and can relate to what you are going through, good luck with your sled.

 

[theflamanguy]

UPDATE: Anyone reinstalling there oil pump, make sure you torque the bolt that threads into crank to proper spec. It came loose and pushed the oil pump out again.
New cover and new oil pump and away i go!!!

 

[rxrider]

Tork spec is 120Nm on that bolt