I thinks its blowed up, not for sure 400ex

[andrew emmons]

I went riding at the railroad tracks where thiers some good hill climbing and went riding on some trails.

i was going home and all the sudden it just died, well first i thought i was just out of gas so i check and had it at least a half tank or more. so i put it on reserve just to try and it wouldnt turn over, then i got worried so i checked my air filter (k&N) and i seen smoke or steam coming from it, and it smelled like somthing burnt.

then i walked about a mile back home and got my dad and me and him pulled it home with his foreman 450, then checked my oil on my 400ex and had just enough to cover my oilpan but i dont no if its blown up so i need some adivce.????????

but i need some advice because not for sure if its blown up

[alaskin 450R]

first off, what kind of engine work have you had done?? its not an easy task to blow up a four stroke. when you checked your oil were was it, its better for it to be tords the high mark but in between the low and high is good too. try taking your carb out and seeing if there is anyting pluging your fuel line. when you were pressing the start button was it trying to start?? are you getting any compression? was it making a weird sound before it stopped? a friend of mines 250R was making a hissing sound before it blue up.

thats all i can think of man, hope you get it fixed

[Rip_Tear]

More info is definately needed. Does/did it make any loud odd noises (crunk, crack, bang etc?). I assume from you oil thing, you are saying it had little to no oil in it? I'm going to bet at that that you siezed the piston... If so you'll want to tear the piston out and at the least put new rings in it, if you didn't fry anything else... (piston, cylinder, vavles etc)

[m1ke]

No good. Remove the crank hole cover on the left side, put the appropriate socket on, and turn counter clockwise gently. If it does not move your engine has internal damage (either seized piston, broken crank, or other.) Do this before anything else. If everything's ok, you can start by taking a compression test, and making sure it's getting fuel.

Note do no use starter to test crank as you may burn it out or damage some parts.

[alaskin 450R]

if it is the oil thing and you did seize your piston i would bore it and hone and get a high compresion piston.