Hey all,

If you read my recent thread https://cbrforum.com/forum/general-t...gasket-156232/ I've been having problems with the cooling system. I also mentioned that I was concerned about the wear on the NEW water pump. Now I'm wondering if that was a 'foreshadowing' of this happening (or maybe it's unrelated, idk)

Couple days ago I was cruising at a nice 60-65mph (cool breezy day; 69F) when my bike suddenly started overheating. As soon as I noticed the overheat light, I pulled over. By the time I pulled over the temp gauge was reading 270F. My bike spewed some coolant out from the overhose (which is common from an overheat if I know correctly) I'm not sure how long it was before I noticed the overheat light, but when I went back and checked my gopro footage the light was definitely not on a minute before pulling over, so the light was on for a max of 1 minute.
I tried limping it, adding some coolant and keeping a close eye on the temp gauge. I did not even make it a few minutes before temp reached 230 so I gave up on limping it and I had it towed to someone's house nearby (very grateful to them for the offer as I was VERY far from my place - bikers community is a very lovely and special one) Everyone helped me check for leaks, thermostat and temp sensor. We checked the water pump last (as it is NEW, and had a little over 3300 mi on it at this time) and found THIS:

That is the back side of the water pump (which goes into the engine side) There should be a shaft there that drives the impeller, it seems to have twisted or slipped out. It is MIA for now, I have yet to pull the oil pan.

Here's a photo of my old water pump for reference (I tried pulling the shaft out, it is on there solid)


This is an OEM Honda water pump from Partzilla, with barely 3300 mi on it since install... !!!

My questions are:

1) How common is it for a water pump failure like this? What exactly causes this to happen?
2) Anything I should check for, aside from changing the water pump and coolant (obviously)?
3) How much damage could the fallen off shaft have done to the engine? I'm hoping I'll find it in one piece in the oil pan for now.
edit: 4) How much damage do you think I did by riding for a minute or under while overheating....

I'm so mad! I thought once I install a new oem part that's something I don't have to worry about. I swear this bike has neverending problems LOL! :/

 

Hi ,never seen this before, almost looks like shaft has sheared, if you can see the shaft in the engine hopefully it wont have fell into the engine ,as the groove you can see on the pump shaft "marries" with the oil pump shaft (male and female) and that should have held it in place, the only way to retrieve it would be to drop the oil pan , you should be able to see where the two shafts join, as the water pump shaft is now useless , you could get a set of grips on it and try to move it out, also take off the clutch cover and take/inspect the oil pump chain and take that off the sprocket so as not to damage the chain in your efforts. Read your previous post is there any chance the garage you took it to can put this right. Your going to need some height to inspect

 

It did fall in, as I mentioned the shaft part is "MIA" right now. Gotta take the oil pan off to see first. I may look into getting a uhaul trailer or something to tow it myself. I installed the water pump myself (not that shop) but I don't think it was an installation issue as it ran fine for 3300 mi. But I may take it to that shop anyway as it's my usual shop and I trust the owner, I could do it myself but the oil pan gasket sounds like too much of a headache rn, had enough scraping old gasket when I did the clutch last time without the pain of oil dripping down added on top....

 

The shaft part is magnetic so I attempted fishing it out with a magnetic tool, no dice.
Thankfully the shop found the piece in one very clean piece:



I guess I learned that nothing is 100% reliable! Not even new OEM parts!