My First Weep Hole Experance....

well i did a search for "waterpump" and i found a TON of info, really good info...

anhow problem is it seam to be kind of out of i am going to start a new one because i am about to tackle this problem....

from what i have read i need to buy these parts: Counter Balancer Shaft Bearing, Waterpump Bearing, (2)Seals - (1)inner (1)Outer, and Waterpump Shaft.

Does that seam right? has anyone did a step by step write up on replaceing this stuff? i dont have a service manual yet and any help would be great... i would like to get this done before next weekend...

You can probably get away with just replacing the seal and copper washer. If it continues leaking or the seal doesn't hold for long, you may need to replace the impellor shaft. I just changed my seal while I was installing the Boyesen water pump and impello. A job that took under 10 minutes. The book says to change the bearing and transmission seal but to do that you have to pull the casing off. Nine times out of ten you will be good to go not doing this unless the shaft and bearing wear are evident.

ok... i was just think about doing the whole shebang since i just bought it... do you know a part numer for the outer seal and washer?

91211-KA3-761 Seal, Water Pump

90447-KE1-000 Washer, Sealing (7mm)

Thanks! now how about some info on changing it... :-) btw where did you get these part numbers?

I had my second weep hole experience yesterday, before I went riding I checked the coolant and it looked alittle low, but I could see it around the fins well I thought ok it is fine. It was not fine about 1-2 hours into my ride I noticed the bike was very hard to start as it started 1st kick when I pulled it off the trailer. So I checked the coolant, almost completely empty and I had been riding extremely hard. My first thought was "oh shi*t that is not good". I knew it the wasn't blown up but it came close, so I took it back to the trailer and loaded it up. I hope that a new water pump seal fixes it if not then looks like I will be getting a new shaft and bearing. :naughty:

this counter balancer bearing that everyone speaks of... is it number 7 in this diagram water%20pump.jpg

i think i am going to go ahead and just rebuild the whole water pump... i have to change the fluids anyhow... to take the right side case off is it just bolts? or is it pressed on.. and is that bearing pressed into the case? someone really should do a right up on this with lots of pictures if its such a common problem... i think i might give it a shot.... :-)

anyhow here is my parts list sofar.. i think i have everything that needs to be replaced...

91211-KA3-761 SEAL, WATER PUMP

90447-KE1-000 WASHER (7MM)

91001-KA4-003 BEARING (12X28X7)

91201-965-000 OIL SEAL (12X22X5)

You might want to have the gasket on hand

19226-MEB-670 Gasket, Water Pump

If the shaft is bad, nicked, etc.


The counter balancer bearings are on another fiche. I replaced mine this winter. I forget which one is more prone to wear. There is a pin roller and a ball roller bearing. This is a job and a half. Better to leave to a dealer. The water pump bearing is pressed in and out. The servive manual does a decent job explaining the process.

ohhh... ok... well ill probally just get the seal and washer in that case... ill check it for wear but i thought that was the "notorious bearing" hopefully mine is ok... how exactly does the water pump leaking effect the countershaft bearing? the counter shaft is what your front sprocket mounts to right?

It's not the counter shaft it the water pump shaft and bearing. Me thinks the bearings wear out a little, causing the shaft to wobble ovaling the inside of the seal causing the leak. My shaft had some crud on it so i changed the whole shebang. Oil seal, shaft, bearing and water seal, with right side gasket.

I must have miss-understood the manual. I think mine is leaking also right now... I'll find out for sure this weekend. I didn't even know about that weap hole till yesterday and I've been fighting a coolant lose issue for over a year. Always thought it was lack of air flow and radiator/reservoir issues but looking at the weep hole it's looks like it's been leaking for a long time!!! Anyways, the manual made it look like the seal was on the outter case and that you needed a slide hammer or something to get the bearing out. Am I looking at totally the wrong part cause that break down on the service honda link a few back looks like you just need to pull the cover and impeller and then the bearing and seal are behind that...

Is the boyesen upgrade worth it? I'm switching to engine ice after I do this replacement if it turns out that's the problem. I'd like to not have to worry about coolant anymore!!!

ohhh... ok... well ill probally just get the seal and washer in that case... ill check it for wear but i thought that was the "notorious bearing" hopefully mine is ok... how exactly does the water pump leaking effect the countershaft bearing? the counter shaft is what your front sprocket mounts to right?

It's the counter BALANCER bearing, not the counter SHAFT bearing.

The counterbalancer is right behind where the water pump is. In fact, the water pump impeller shaft is driven from the counterbalancer bearing.

If you have a problem with water seals going bad frequently, the problem is almost certainly that the counterbalancer bearing is loose in its seat (and as it wobbles around it makes the impeller shaft wobble too, which causes the water seal to eventually give up).

It's actually fairly easy to fix (by "fix" I mean "temporarily" solve the problem in a more lasting way than just replacing the water seal).

1. remove coolant

2. remove transmission oil

3. Remove water pump cover

4. Remove entire right side case cover

5. You'll see the counterbalancer directly behind where the impeller shaft goes (it's a gear with half of it covered by a weight, connected to the crank gear)

6. jam a spare penny between the crank gear and the counterbalancer gear to hold them in place, then undo and remove the counterbalancer gear and weight

7. Underneath you'll see the bearing. I bet you can wiggle it around in its seat with your finger. Remove the two retainers on top of the bearing and remove the bearing (it'll probably just fall out if it's loose enough).

8. Peen the bearing seat in 10-15 places

9. Reinsert bearing -- it should now be a tight fit. Even better if it needs mechanical encouragement to get back into its seat.

10. Replace counterbalancer gear and weight and tighten.

11. Replace water seal in the water pump, check the impeller shaft while you have it out to see if it's still in good shape (replace if not).

12. Reassemble and refill everything and ride!


me too... i have 1/2 gallon of engine ice waiting to go to its new home as soon as i get this stupid seal in from my loacal bike shop....

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