2010 YZ450F Oil Leak

17 replies to this topic
  • oneindustree

Posted May 23, 2015 - 02:30 PM




New to the forum and 450 dirt bikes. Recently bought a 2010 YZ450F bike and love it. I failed to notice the oil leak when looking the bike over, and I'm wondering if this problem is simple, or needs to be taken to a shop to be torn down. On a scale from 1-10 of my mechanical skills, I'd say I'm a 4. The pic shows the oil leak; looks like the left side crankcase cover. Are these plastic plugs and oil seals, or is this something related to a cracked case and I'm looking at a rebuild? Any help for this newbie would be appreciated. Thanks!

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  • yzf.jpg

Edited by oneindustree, May 23, 2015 - 02:30 PM.

  • 03yzf450-kuke

Posted May 23, 2015 - 05:09 PM


If you mean its leaking from around that cap its probably just tge o ring behind it

  • oneindustree

Posted May 23, 2015 - 05:22 PM


Yeah man, that cap. I looked at the owners manual, I'm not seeing an O-ring behind the cap. I'll prob order the oil plug set and replace it and see what happens. Have you needed to replace these before?

  • 03yzf450-kuke

Posted May 23, 2015 - 05:38 PM


Never had to replace mine. I have an 03 and an 04 yzf and a 79 honda they all have o rings not 100% sure bout your bike though but its gotta seal somehow

  • oneindustree

Posted May 23, 2015 - 06:10 PM


These are just plastic caps to be able to see inside at the crank correct? I was worried it was part of the crank case cover and had to be replaced

  • grayracer513

Posted May 23, 2015 - 06:19 PM


The center one gives access to turn the the crank so you can use the top one to locate the timing mark.

  • BGoyins

Posted May 23, 2015 - 06:32 PM


Hopefully seller didn't represent as 2010. Must be something earlier. Looks very clean.

  • grayracer513

Posted May 23, 2015 - 08:45 PM


Definitely not a 2010.  '08, '09 maybe.

  • x_JT_x

Posted May 23, 2015 - 10:31 PM


I'm just saying but that looks like a stock photo of a new bike.. I'm going to guess that's not the actual bike.. But for sure not a '10 in that picture.

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  • oneindustree

Posted May 24, 2015 - 06:28 AM


Guys, thanks for the responses. you're correct, the bike shown is another photo on the net. Here's an updated photo of my bike. Is it odd the crankcase cover is black,or did Yamaha build some 2010's with this color?

  • oneindustree

Posted May 24, 2015 - 06:33 AM


Jeez guys, sorry still getting used to this site

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  • 20150523_100815.jpg

Edited by oneindustree, May 24, 2015 - 06:37 AM.

  • BGoyins

Posted May 24, 2015 - 08:41 AM


Jeez guys, sorry still getting used to this site

Ahhh. Good, I was hoping someone didn't try to scam you. The side cover has been painted black. Inspect the mating surface of the plug O-ring to make sure it's not causing the oil leak.

  • oneindustree

Posted May 24, 2015 - 09:15 AM


Well damn. I'll pull it off and sand it down. Drain the oil, take the cover off? Is it that simple?

  • x_JT_x

Posted May 24, 2015 - 09:26 AM


Well damn. I'll pull it off and sand it down. Drain the oil, take the cover off? Is it that simple?

Pretty much. You could get away with not changing the oil if you tipped the bike over on its side too :D

I'd try some spray paint remover and a power washer first. You may be able to avoid sanding.

Edited by x_JT_x, May 24, 2015 - 09:26 AM.

  • oneindustree

Posted May 24, 2015 - 09:34 AM


You guys are awesome. I'll ask my questions about riding tips in the general forum section

  • grayracer513

Posted May 24, 2015 - 09:35 AM


No need to drain the oil or remove the cover. The problem is almost certainly damage to the O-ring or dirt under it, or it's just missing. Paint shouldn't be an issue, although there could be a built up dried drop on the seal seat.

If you run the bike for about a minute before you open that up, no significant oil will be lost, since the bike is a dry sump system. Read about that in Common Threads.

  • oneindustree

Posted May 25, 2015 - 07:33 PM


Anyone happen to know Allen wrench size for these two plugs?

  • x_JT_x

Posted May 25, 2015 - 08:43 PM


If I recall the smaller of the two is an 8 Allen,. You should really have a set and test them though

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