Oil leak

3 replies to this topic
  • tk4215

Posted September 28, 2014 - 01:20 PM


2002 yz426
Following an oil change my bIke has developed an oil leak. While riding I believe it is coming out the breather tube. I check the oil several times during a ride and it doesn't change.Its been sitting for a week and a moderate amount of oil has leaked into a pan. The bike starts easy and runs very good.

  • grayracer513

Posted September 29, 2014 - 06:59 AM


How many drain plugs did you remove, and much oil did you add back?





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  • tk4215

Posted September 29, 2014 - 10:27 AM


Both drain plugs. And I installed a new crush washer and oil filter. Approximately 1.5 quarts

  • grayracer513

Posted September 29, 2014 - 10:49 AM


Sorry, I posted the wrong link this morning.  I blame it on the coffee machine. Fixed it. (the link, that is. The coffee machine is still broke)


From what you have said, you're not overfilled, but you should double check that on the dipstick within one minute of shutting down the engine.  If the oil level is correct, the oil could be coming from the breather, and to an extent, that's normal.  Especially with an older bike that may have "tired" rings, when ridden hard, oil will find it's way into the breather hose due to the chaotic air pressure changes in the crankcase, and then it will drip out of the tube as it sits.  One way to isolate this is to pull the hose out of its retaining clips and stick it into a pan, jar, or bottle far enough away from the rest of the engine area so that if the hose drips it goes in that container, while nothing else that leaks can reach it. 

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