3 part engine question

2 replies to this topic
  • Will.A.R.

Posted January 28, 2015 - 12:01 PM


2004 yz450 on the end of the shift can there's a small brass contactor for the neutral switch. When I disassembled my engine I noticed it had an oring on it that didn't look quite right. Is this supposed to be that large and what's its function. See picture below. 3rd question is other than the crank bearings and the two that are sealed on one side, are any of the rest of the case bearings directional?

Attached Thumbnails

  • 1422475316221.jpg

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • grayracer513

Posted January 28, 2015 - 01:08 PM


The O-ring may have been used as a substitute for the spring that's supposed to be under the contact pin to push it against the tracks on the switch.  Can't think of another reason for it. 


Other than the bearings you mention, I don't recall any others that are specific as to which way they face. 

  • Will.A.R.

Posted January 28, 2015 - 02:40 PM


Thanx! The IPB was showing the oring but I didn't see it in the maintenance manual. Guess I'll ditch it since the spring is there and seems to function as advertised

Related Content


Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

Megabomb Fitment by 288yz450

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply

2016 YZ450 by CaptainKnobby

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 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.