Nytro motor down

[snowfix]

my front mount nytro has worked like a charm unitl yesterday. Half way into a climb it lost power and oil/smoke rolled out from the engine compartment. No bang, pops, or farting, just lost power and died. Crank rollsover but the resistance is minimal. I started it quick once and it will start but is certainly not running right. No knocking, just sounds ill.


Im still out at the hill enjoying the hot tub and beers while the boys play, so I thought I'd do some arm chair enquiries before I get home and start ripping it apart

 

[mmaman207]

minimal resistance sounds bad... rings ...or lack there of.

 

[kimoajaj]

Sorry to hear this.. how much boost were you running? hp ?

 

[nate007]

Start with a compression and leakdown test. Hopefully it rules out a few things.
Keep us posted.

 

[snowfix]

No compression on the PTO cylinder. It blew out the valve cover seal too which is where all the oil must have been coming from. I assume a hole in the piston would pressure up the crank case and cause this.

I was running less than 15 lbs when it blew but i had just had my map upgraded and hooked up the air fuel gauge for a loop feed back. It was wierd because it was running great.

So the big question now I guess is how much damage? Is it reasonable to think just pistons? I pulled the motor to take to shop next week. I'd sure like to have a peak inside first.

 

[snowfix]

here's confirmation of my issue

 

[mulot30th]

Only 15 psi did that? must have had an issue somewhere efi?

 

[tapex_07]

Is it just a cracked piston? Id say your lucky it just died and dint fubar the motor!

 

[t_thall]

I've seen this on a 450 motocross bike, it was from a cold engine, bike was sitting for about 45min during an ambulance wait then the ref gave zero notice and started the race...

 

[nolimits]

jim at osp has forged pistons in stock for that sled you may also want to do his stud and oil pump upgrades those motors are solid except for those issues
jim wentworth