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YZ 250 burning coolant

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Hi everyone, I'm new to the forum. Been visiting for a while and finally decided to join.  I rebuilt the motor myself bottom to top and with just 5 hours on it, it started using coolant.  :banghead:

I was riding and stopped for a break and then it would not start.Finally after about half hour of kicking it went. It ran like crap for about 5 minutes and then exhausted a huge cloud of smoke and I shut it down and called a friend to come pick me up. When I opened the radiator cap it was empty. This is very disheartening as this bike has been nothing but trouble for me from day 1. :smashpc:

I was wondering if anyone could tell me what gasket could have failed or what could have caused this. I used permatex gasket maker (not yamabond) as recommended by the machine shop I bought my parts from and thinking maybe caused my problem? or maybe the aftermarket gaskets? Just tell me what you think. Here's a picture or the bike because everyone loves pictures. 

IMG_20140526_224158.jpg

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A common spot is the head o rings.  They get pinched on assembly a lot.

Base gasket.

Theres also a rubber oval ring between the cases that gets forgotten occasionally.

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Could be the head or base gasket. Could also be a cracked or warped head, cylinder or case. Start with the head and work your way down.

If it was the oval oring, coolant would leak out the bottom of the case.

Edited by bg10459

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head gasket. pull the head and replace the 2 o rings that seal it up. i usually take a b.b. size dab of grease and coat the oring in it so it stays in place in the jug recess when installing the head.  i'm assuming you weren't riding super tight S.T.  and boiling the whole way prior to checking the coolant. right?

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Has to be the head gasket. Do like schrode said

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head gasket. pull the head and replace the 2 o rings that seal it up. i usually take a b.b. size dab of grease and coat the oring in it so it stays in place in the jug recess when installing the head.  i'm assuming you weren't riding super tight S.T.  and boiling the whole way prior to checking the coolant. right?

I sure hope you are right in saying the head gasket oring. I don't know what you mean in saying "riding super tight S.T." but I was not boiling over coolant. Thanks for the assembly tip. I will post back in this thread with my findings. Could be a while.

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