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2006 KX250f Overheating???

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I bought a 2006 KX250f yesterday and decided to go for a little ride. The Anti freeze was topped off when I left and when I got back there was almost none left. Also while riding a buddy informed me that the bike was puffing some white smoke and it was very hard to start. I got home and parked it and noticed milky oil almost like the coolant was in the oil. Any ideas as to what is wrong with my bike? I'm new to these liquid cooled race bikes and have no idea as to what the problem could be.

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Prolly a head gasket. You have water not staying separated from the rest of the engine. White smoke and milky oil are two definitive signs.

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that is kind of what i've been reading but is that expensive/ hard to fix? and is it possible that the head is warped too?

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Not terribly hard to fix. Thing is you'll be halfway to a new top end. If you don't know the bike or how many hours you might want to go ahead and do that. Other issue is why did the gasket fail? 06-08 supposedly had issues with getting hot, but my 06 never did.

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the guy i bought it off of just put a brand new top end in and it has 5 hours on it but from reading i've kind of hypothesized that maybe the water pump failed which let the engine over heat which maybe warped the head a blew the gasket. But that is just a guess from reading. also it has a new radiator cap so i put the stock one back on maybe that will help solve the problem in not sure yet. But earlier it was kind of hard to start i got it started once before i had to leave.

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If you have not done this yet ... you really need to pull the head, cleanup the gasket surfaces and torque down properly. I am assuming you have alreadt drained the oil and put on fresh. do the following.

Take the seat off and the fuel tank with the front side plastics.

Drain the coolant. Remove the head cover, the cam chain tensioners, and the cams. Loosen the 4 head bolts and remove the head and the gasket. Then you can inspect the top of the piston, the surface of the top of the cylinder, the surface on the bottom of the head. You can also have a nice look at the valves.

Clean those gasket surfaces sparkly clean with scotchbrite. Wipe dry. Inspect the gasket and decide to reuse or replace.
Put the gasket on and the head on and those four bolts. Torque down properly (criss-cross). Go do something else for 30 minutes. Come back and now retorque. Put the cams in, set timing, torque caps properly. Put chain tensioner back in. Put head cover on, tank seat. Refill with coolant. Go for a test ride.

If after that it is still loosing coolant to the oil, then your next fix to go after is going to be the water pump seal.

Good luck!

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These things let go of right side seals five times before a head gasket does once. You dont use condoms twice. Its your water pumps shafts seals. There are two. One that seals oil in the motor. One the seals water in the pump. 

Do what Face says and your bike will be good three times as long.

Do what I say and youll spend $40 and be riding in an hour.

And if you dont use torque specs, enjoy the next problem

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Yes do both. 

Maintenance.

The impeller IS the water pump. Its those seals. You have to pull off pump cover. Pull off impeller. And pull off right side. One seal inside. One seal outside. 

Just first, get a shop manual, then get a torque wrench, then get a right side gasket/seal set and get a top end gasket/seal set.

Take it apart. Clean up surfaces. Seal up. Torques specs. 

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The chances weigh WAY heavier with seals than a cracked head would happen. Ive dropped motors off loading docks to concrete(argh!)...no cracks 

That heat is going to ruin something way softer than that heads metal.

If its new to you, change all of it. Clean slate feels amazing. 

 

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