08 450

3 replies to this topic
  • SomeSortOfThing

Posted June 04, 2016 - 05:49 PM


Hello! Just picked up a used 2008 yz450 f that is, overall, in great condition. My last two rides, the bike was leaking coolant bad (no coolant in oil, though). Did some digging around on here and YouTube, and seems the seal and impellar shaft like to go out on these. Anyways, got a water pump seal replacement kit (inner and outer seal, o ring that goes to the water inlet, and crankcase gasket) and got it all buttoned up Wednesday night. As soon as I put coolant in, it just starting pouring out from what looked like between the cases (bike was off). Took it back apart today and everything seeeeeemed to be installed correctly, and the impeller shaft looks really good. Now, here is my issue: when the bike is sitting on the stand, it doesn't leak. When I tip it to the right, it doesn't leak. When I tip it left though (shifter side) it starts running coolant from, as far as I can tell, that water inlet from the radiator hose. This is when the bike is on OR off. I am getting incredibly frustrated and would like any help or ideas.




  • SomeSortOfThing

Posted June 05, 2016 - 08:13 AM


Here's where it's coming from. Doesn't look like anything is coming from weep home but it's hard to say

Attached Thumbnails

  • 1465143150214.jpg

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

Posted June 05, 2016 - 01:29 PM


There's a rubber o-ring that seals the inlet tube where the coolant is laying in the picture. That's where I would start.

  • SomeSortOfThing

Posted June 05, 2016 - 01:31 PM


^^ 3 different o-rings later I found one that sealed it. Thanks

Related Content


yz400f throttle bog by yz400fmaniac

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

First Hare scramble tips by dhend8

Dirt Bike   General Dirt Bike Forums   General Dirt Bike Discussion
  • Hot  33 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

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

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 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.