Oil leaking out of hole on right side of cylinder?

3 replies to this topic
  • centralmax

Posted July 18, 2009 - 07:22 PM


What is the hole on the right side of the cylinder and why is there oil leaking out of it?

Posted Image

  • 426 NOOB

Posted July 18, 2009 - 07:45 PM


That hole is a drain for the spark plug area. When you get water in there it allows it to drain rather than build up. I doubt its oil, but more likely dirty water coming out and if it is oil, tighten up your spark plug.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • papxj

Posted July 18, 2009 - 08:22 PM


Did you wash your dirty bike and spray dirty water up there? It's probably water. Taste it to be sure...

  • grayracer513

Posted July 18, 2009 - 10:05 PM


If you have oil coming from there, there are two possible causes

  • The spark plug could be loose enough to leak combustion "goo" around it's base (not likely, unless you're burning a lot of oil)
  • The cam cover gasket is leaking into the plug well

Related Content


Help with 2000 yz426 by weekend woods racer

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  36 replies

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F

Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies

Is the 2016 GYTR Yamaha YZ450F too fast? by Fryboy

Dirt Bike   Special Interest Forums   Pro Racing
  • * - - - -
  • Hot  241 replies

100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies

yz400f throttle bog by yz400fmaniac

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • * * * * *
  • Hot  28 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.