small puddle of liquid on top of case

1 reply to this topic
  • 00yzryder

Posted April 11, 2016 - 07:57 AM


So trying to figure out WTH it is. I'm assuming its either gas or coolant but it doesn't smell. Basically it comes up a little forward of where the carbis over and directly on the line where the cases meet. Every ride there is a quarter sized puddle and i look around and don't see anything leaking from the carb or the head so i'm starting to get a little irked at it. Has anyone else had an issue or can point me to possible areas it might be leaking from?


bike is an 07 yz 450.

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  • grayracer513

Posted April 11, 2016 - 08:57 AM


Could be oil.  There is a pressurized passage that crosses the crankcase just below and behind the cylinder that feeds the top end and the transmission shafts.  The leak might come from the case joint (which would be quite unusual), or from the seal on the clutch release arm.  The bore the release arm runs in is used as an intersection of three oil ways. 


Gasoline would not really puddle on the case.  It would either sheet out or evaporate, or both.  If gas, it should easily be absorbed by a piece of paper, and when moved away from the bike, you should be able to light it with a match and see it burn like it had gas on it.  If it is coolant, it will rinse off your finger tip with water.  If it's oil, it won't. 


You can also pin down the source by dusting the area with talcum power (baby powder, foot powder, etc.).  The leak will leave a trail in the powder that is more easily visible.

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