Water Pump

3 replies to this topic
  • LBZYZ426

Posted November 21, 2008 - 12:56 AM


So how do you take out the water pump? Searched the site and read, put in gear, push rear brake and loosen.

It just keeps turning and turning, gets tight then loose so on and so on.

What could be wrong here :thumbsup:

  • matt4x4

Posted November 21, 2008 - 04:23 AM


If you are still able to turn it when it's in gear and rear brake on while you're trying to remove it, then it may well be that the key on the shaft (backside) is messed up.
if it were my bike, I'd dump the oil out, take off the case cover and see where the problem is, once you have the case cover off, you can clamp the key portion of the shaft in a vise and spin the impeller off.

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  • grayracer513

Posted November 21, 2008 - 06:45 AM


What's wrong is you are not supposed to remove the water pump impeller from the shaft without removing the engine cover. Doing it from outside runs the risk of breaking the drive tab or damaging the balancer shaft, and unless you remove the shaft, you really can't inspect it for wear well enough.

The inboard end of the shaft has a pair of flats ground on it (not the drive tab, the flats are farther up on the fat part) so that it can be held with a 12mm wrench. Yes, they can get to be very tight, and yes, they are right hand (normal) threads, so you turn the impeller counterclockwise to remove it.

Tip: put the 12mm on the impeller shaft, then stick one of the case screws into the case backward and let the wrench rest against that while you hold the case down and loosen the impeller. It will save you a lot of frustration.

  • 642MX

Posted November 21, 2008 - 04:41 PM


Grayracer is right, thats the correct way. But..... I've removed a bunch of them with just a 3/8 impact. The impact kind of sneaks up on them and they pop right off, I haven't damaged one yet. (yet.. may be the key word).

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