Blown head gasket?

[jace98]

I need help i just bought a 06 yz250f bike runs great.the other day i noticed coolant dripping from the over flow tube when i cracked the throttle more came out,i then found coolant in my oil so i assumed water pump seals so no big deal i replaced them the bike no longer leaks from the over flow but i still find coolant in the oil i have noticed a little white smoke but can anyone tell me if i need a new head gasket please?

[firstnewbike]

what does your spark plug look like if it is spot less super clean then there has probably been coolant in the combustion chamber

[jace98]

I have not checked yet i will first thing tomorrow the only thing is that the bike starts and runs perfect do you know how bad this could hurt the engine? i plan on fixing it as soon as i find out whats truly wrong i just hope its not to far gone not looking for a whole rebuild.

[jace98]

Plug is pretty dirty

[firstnewbike]

have you done any riding in water lately, coolant in the oil, where are you seeing it,

milky on the dip stick, milky under the fill cap,?

it could be moisture condensation with in the engine

[yamahakid88]

Are you noticing a loss of coolant over time as soon as you fill it up? Most likely you will need a new head gasket, if it is puffing out white smoke it is burning water of some kind.

[jace98]

I am losing coolant ,have not rode in water and i first noticed the milky oil when i drained the oil when i did the water pump seals but it seems like it almost got worse after i did that is their anyway it could be the impeler shaft?

I am losing coolant ,have not rode in water and i first noticed the milky oil when i drained the oil when i did the water pump seals but it seems like it almost got worse after i did that is their anyway it could be the impeler shaft?

Edited April 22, 2013 by jace98

[yamahakid88]

It could be she shaft, sometime it gets scored and can let water through, but I would guess its the head gasket, not the impeller shaft, and are you sure you put in the seals correctly? I know sometimes they can be flip flopped

[Charlie755]

I need help i just bought a 06 yz250f bike runs great.the other day i noticed coolant dripping from the over flow tube when i cracked the throttle more came out,i then found coolant in my oil so i assumed water pump seals so no big deal i replaced them the bike no longer leaks from the over flow but i still find coolant in the oil i have noticed a little white smoke but can anyone tell me if i need a new head gasket please?

Its a bad head gasket. Any time you have coolant being pushed out the overflow tube when you give it throttle (especially under load) this is typically the cause. What happens is cylinder pressure is leaking into the cooling system and over pressurizing the cooling system to the point that the pressure overcomes the radiator cap and forces coolant out the overflow tube.

[yamahakid88]

Its a bad head gasket. Any time you have coolant being pushed out the overflow tube when you give it throttle (especially under load) this is typically the cause. What happens is cylinder pressure is leaking into the cooling system and over pressurizing the cooling system to the point that the pressure overcomes the radiator cap and forces coolant out the overflow tube.

Sometimes a bad radiator cap can piss coolant out the overflow as well. But I like your theory

[jace98]

Ya im thinking head gasket because of the coolant in the oil thanks for the input guys!

[jace98]

Head gasket looks all sorts &%$#@!ed up but when i removed the head a dowel fell out and near where it fell i found this spring is their anyway its from the bike? God i feel stupid!

[jace98]

[yamahakid88]

It almost looks like an exhaust spring, if not, I doubt it belongs to the bike. There are no other springs on a bike that are like that. As for the dowel, be more careful man, you don't want something dropping into the bottom end, stuff clean rags around the connecting rod if you haven't already. For some reason I alway hear about head gaskets blowing on the Yamaha 250f's, mine did the same.

[jace98]

Yea i did not think it was from the bike but i will be extremly careful for now on! Thanks again