oil pump

2 replies to this topic
  • jrcgaf364

Posted January 07, 2006 - 08:23 AM


On a yz400f do you have to prime the oil pump after a complete teardown? If so do how do you do this? :applause:

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

Posted January 07, 2006 - 08:41 AM


I would suggest Priming ANYTHING after a teardown.

i would say .. pull the spark plug out. and kick the bike like 25 times.
put the spark plug back in and start up .

run it for like 10-20 min, then change the oil . and filter

  • grayracer513

Posted January 07, 2006 - 10:49 AM


It's obviously better to fill the lube system prior to starting the bike, but with the trochoid rotor oil pumps use in the YZF's, priming is unnecessary.

You should, however, pre-oil the pump rotors, both of them, as you assemble the engine, as you should the rest of the motor. Since it's a dry sump with the oil supply carried higher than the oil pump, there is no real worry about the pump being able to lift the feed oil for the first time, either. If you have properly pre-lubed the engine components as you assembled them, all you have to do is to take it easy with the throttle for the first 20 seconds, and you'll be fine.

But, if you think you really do want to pre-load the lube system, here's the way to do it. Remove the oil filter, and leave the cover off. Hold the compression release and crank the engine until oil is pumped into the filter well. Lay the bike on its left side, put the filter in place, and fill the filter well with clean oil. Then install the cover and stand the bike back up. Now loosen the oil feed banjo bolt at the cylinder head an crank the engine until you see oil delivered. The system will then be fully pre-filled, and will deliver oil immediately on start-up.

Related Content


James Stewart back on a YZ450F by YamaLink

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

Wilson the Blue Privateer by jetfuel

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  50 replies

Megabomb Fitment by 288yz450

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

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

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