Is the dowel pin on the water pump cover important?

[Kurt]

I replaced the water pump cover on my bike today and did not notice until everything was buttoned up that the pin stuck in the old cover when I took it off so the new cover was installed without any dowel pin. Is this critical to have installed? It seems like it would just be helpful for aligning everything when installing the cover but I got it buttoned up no problems and there don't seem to be any leaks. I would rather do it right though so I can pop it in tomorrow morning if I need to.

 

The dowel pin Im talking about is part 36 on this diagram:

Shop 2015 Yamaha FZ-07 WATER PUMP OEM Parts Diagram - RevZilla

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2015 Yamaha FZ-07 WATER PUMP assembly detail & product fiche. Shop original factory replacement parts at RevZilla today!

 

[Evill_Ed]

It may help index the cover on the pump to provide even or correct clearance with the impeller. This could affect flow. That’s my guess.

However, if the Yamaha Engineers designed it in there, there’s a good reason for it.  I’d put it in.

 

Ed

[randy2100]

I would reassemble with the pin to minimize the risk of future leaks.  The bolts have a looser tolerance than the pin, so the cover could move more due to vibration or heat expansion.

[Kurt]

Good points, I went ahead and replaced the pin. Went a lot faster the second time around.