06 YZ450F Crank Seal...


22 replies to this topic
  • grayracer513

Posted August 08, 2010 - 02:20 PM

#21

I just looked over both the '09 and '10 manuals, which are higher grade PDF's than the older ones, and it is clear (at 400% enlargement) that the seal is illustrated with the open side (the side with the spring loaded lip) installed facing the crank.

I am certain that I've seen them installed this way, but I've also seen them the other way 'round. It appears that Yamaha considers it correct, although if the interest was purely in sealing the oil pressure into the passage, it would be the other way around. But obviously, there is no harm in having oil "leak into" the primary case, so the engineers may have deliberately called for this in order to have the resulting leak serve to lubricate the seal and reduce the wear to it.

In so doing, they must have determined that the oil pump will provide adequate volume and pressure to the system in spite of the loss, and it may even have been a way to limit pressure.

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

Posted August 08, 2010 - 02:57 PM

#22

it may even have been a way to limit pressure.


Im guessing this route, or basically its designed to cause differential...

  • thurgood

Posted August 08, 2010 - 03:22 PM

#23

Interesting - an oil pressure regulating lip seal. I've seen lots of pressure regulation methods before but not this one, though it sounds reasonable enough to me.

If the manual show it "backwards" and others have found them this way with no issue about lack of oiling to the bottom end of the engine, then I'll install it with the open side facing the crank.

Thanks for the replies guys.





Related Content

Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
Forums
Photo

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies
Forums
Photo

Chubby dad, looking at bikes , First trip to the orange/black forum ! by Slow_ride


Dirt Bike   Make / Model Specific   KTM   250-530 EXC/MXC/SXC/XC-W/XCR-W (4-Strokes)
  • Hot  28 replies
Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
Forums
Photo

James Stewart back on a YZ450F by YamaLink


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies
 
x

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.