can anyone tell me what happened??

[brianRM250]

So I was out riding last weekend for about 20 minutes on my 03 RM250 and I started hearing a weird vacuum type squeal coming from the engine. Then a few minutes later i hear a clanking noise and the bike starts pouring white/gray smoke out of the exhaust and died when I gave it more gas. I checked the gearbox oil, fine and still the right color. Coolant is still full. The bike is spewing oil from the front of the exhaust and the rear. Did I fry the top end? The bike will still run at idle while pouring smoke out, but when I give it gas it dies.

 

[RM_guy]

Sounds like you blew out one or both of the o-rings the seal the head. The smoke is burning antifreeze.

 

[_JOE_]

You may have trashed the crank bearings. That could explain the clanking and once the bearings go the seals follow, explaining the smoking. How long did you run it after it began smoking?

 

[brianRM250]

I only ran it for maybe 30 seconds after that happened. Just enough to see oil spraying out of the exhaust along with the smoke. That vacuum noise may not have anything to do with it. But it did make some bad clanking noises right before the smoke/oil started pouring out. There is no discoloration to the coolant either. I am leaning towards crank bearings and seals. I assume this requires the engine to come completely out of the bike to fix?

 

[IndyMX]

I only ran it for maybe 30 seconds after that happened. Just enough to see oil spraying out of the exhaust along with the smoke. That vacuum noise may not have anything to do with it. But it did make some bad clanking noises right before the smoke/oil started pouring out. There is no discoloration to the coolant either. I am leaning towards crank bearings and seals. I assume this requires the engine to come completely out of the bike to fix?

Yes, you'd need to split the cases to replace crank bearings.

 

[whenfoxforks-ruled]

So I was out riding last weekend for about 20 minutes on my 03 RM250 and I started hearing a weird vacuum type squeal coming from the engine. Then a few minutes later i hear a clanking noise and the bike starts pouring white/gray smoke out of the exhaust and died when I gave it more gas. I checked the gearbox oil, fine and still the right color. Coolant is still full. The bike is spewing oil from the front of the exhaust and the rear. Did I fry the top end? The bike will still run at idle while pouring smoke out, but when I give it gas it dies.

That is one of the many ways that blowing up a motor feels like. 3 to 400 dollars in parts, minus further catastrophic damage from continuing to start it, to the cylinder, head and crankcase.