03 wr 450 water pump impeller shaft question

3 replies to this topic
  • bigblockchevelle

Posted October 05, 2006 - 03:58 AM


Hey guys, i just installed my new water pump seals and shaft last night as it was leaking out of the weep hole. two questions. 1. Why does the slot that I insert the water pump shaft into (line up with) when installing the cover seem so much bigger than the flats on the end of the shaft? I cant believe its wear related as the end of the old shaft seemed fine. It just didnt seem like a tight fit like the picture in the manual showed. 2. Why does the shaft (once installed in the crank case cover) seem to have movement in and out. When it moved in, it seemed like the impeller was hitting the housing a little? The old one was the same way when i removed it. if anyone could give me any advice that would be great as I have it all back together but it is bothering me. thanks guys

  • Indy_WR450

Posted October 05, 2006 - 09:29 PM


You are just fine. That is perfectly normal on our bikes. :devil:

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  • bigblockchevelle

Posted October 06, 2006 - 03:40 AM


thanks again buddy!!

  • Hot Rod Todd

Posted October 06, 2006 - 06:08 AM


becareful what you read. it is not fine . it is bad. very bad. i've got an '03 wr450, and have had to replace the counter balance shaft twice now. so thats 3 on my bike including factory. the counter balance shaft is what holds, and turns the waterpump impeller. like you said the inside edges to the c/b shaft do not look square!!!! it SHOULD BE! you need to replace both cb shaft and impeller shaft. it is not cheap. but dude, you need to do more work on your bike. do not ride with the c/b shaft like that, you'll only ruin your new impeller shaft. also, to be honest, i haven't read any others are having problems with this, and would bet almost every wr and wr owner are having the same problem. all do yourself a favor and check the two parts and look for wear. that part is easy, its spend'n all the money to replace everything is hard. like i said, i now have a third cb and impeller shaft combo in a '03 wr450. of course i would like to know why and what causes the problem, but it always looks ok until about a year (season up here) later and......
my only guess is that we are constantly blasting the hell outta the slow guys behind us on the honda's!
not to slag indy either, but if you have an '03 like me, you might be surprised to find some rounded edges (like your reply, to this guy that maybe has done more damage.) on your cb shaft too.


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