HELP! wr400 fuel/coolant/oil in block

hi my name is brayden and i have a 99 wr400. today as soon as i fired it up it puked out about a half gallon of antifreeze/oil/gas mixture on the ground out of the vent tube on the left side that comes from on top of the cam cover. what in the world could this be? i drained the oil from the frame and case and it was almost pure coolant and gas. the water pump weep hole leaked before this problem and i just took it apart. the shaft has about 1/4 inch of side to side play in it. Im stumped on what this could be. ALSO, when the bike fired up, there was no blue smoke out the back and it ran just normal. Any help is much appreciated! thanks, brayden

I hate to tell you this, but I get the feeling that you need to take this to a mechanic, or if you've got a buddy that knows how to work on bikes perhaps he can help you. Your waterpump needs rebuilding and I get the feeling this is beyond your capabilities.

i was 90% sure it was that but, i was confused of where the fuel was coming from? the water pump on these bikes i know need rebuilt but that doesnt explain the gas in the oil

The fuel/gas in the oil can be accounted by the fact that you head gasket has blown. This can happen if the water pump is not working or if it has over-heating problems. In this case it sounds like your water pump that was the cause of the blown head gasket.

A word of advice....Don't do anything that you are unsure of.

Hope you get it sorted soon.

The gas can also be from a leaky float valve in the carb and leaving the gas petcock turned on when the bike isn't running (something I was always taught never to do).

I'd rebuild the WP, clean the carb and see what you have then before doing a head gasket or other repairs. Oh yeah, check your valves, timing and cam chain as well.

Mike

I can't see why the fuel would leak into the cylinder given that your float needle is not blocked ,the o-ring is okay & the float is set right. It should not be able to leak into the cylinder if all this is right. First check the plug for signs of water & proceed to leak test or compression test. If all checks out then the cylinder head gasket should be okay.

+1 on ...check your valves, timing and cam chain as well.

I can't see why the fuel would leak into the cylinder given that your float needle is not blocked ,the o-ring is okay & the float is set right. It should not be able to leak into the cylinder if all this is right.

Just wondering, did I miss where he said these things are good and check out on his bike? Unless I missed something I don't see anything relating to the carb in his post and this very well could be another factor why it doesn't start very well. Not saying it is it, but with the limited info he has given us unless the bike has severely overheated blown head gaskets are not that common. Also not saying head gasket not the issue, but on an older bike carbs and top end are the most common reasons starting is hard.

Mike

When I had coolant in my oil, it was a cracked cylinder. It cracked on the intake side and went down 2 inches. I had a to do all new bearings (main, balancer and trans), crank, piston, cylinder and gaskets/seals. When I had a head gasket blow I never had coolant in the oil but it was smoking a lot from the exhaust.

When I had coolant in my oil, it was a cracked cylinder. It cracked on the intake side and went down 2 inches. I had a to do all new bearings (main, balancer and trans), crank, piston, cylinder and gaskets/seals. When I had a head gasket blow I never had coolant in the oil but it was smoking a lot from the exhaust.

It would depend where the head gasket blows. It has more chance of blowing through the water jacket in theory but I guess that's why there is an Drain hole on the water pump to stop that happening. Still doesn't mean that it hasn't happened though.

Also, if the oil can drain into the water & the fuel is draining into the oil that would explain why there is so much fuel in the oil/water.

I'm not saying it is the head gasket but highly likely.

Edited by Barra8

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