Yanmar 1GM10 - Impeller problem

[boatpoker]

The impeller in the OP photograph is junk. The rubber and adhesive on this type will dry out after sitting in the chandlery (or your parts locker) for a few years and the bond between the rubber and brass will fail.

A good quality impeller will have flutes or spines (like a star) on the the brass with the rubber molded around it. This give the rubber much more grab and are much less likely to fail in this manner.

[nilespf]

Vane pumps have to be lubricated both initially and while running. Be sure to put enough lube in and around the vanes for startup and if possible during running can you observe adequate sea water is getting to the input side of the pump? I have a transparent collector/filter assembly to make sure the raw water is being drawn up and into the canister.



pn

[nilespf]

Also I see you have tried dish washing liquid. It may dissolve before an adequate suction pressure/siphoning is established. But long term lube is the water itself. Try and establish if the amount of water getting to the input line is adequate. If the shaft driving the vane is sloppy (worn) you should be picking up a leak out the pump housing drain.
pn

[mattyc]

Well the boat has been on the hard since I sailed up to Maine from the Bahamas in May of 2019. I never did manage to find out why my impellers failed so quickly. I've decided to try an centrifugal 12 volt water pump to be located below the waterline. Does anyone have a ballpark figure for how many GPH the pump would need to be?

[Compass790]

Originally Posted by mattyc

Well the boat has been on the hard since I sailed up to Maine from the Bahamas in May of 2019. I never did manage to find out why my impellers failed so quickly. I've decided to try an centrifugal 12 volt water pump to be located below the waterline. Does anyone have a ballpark figure for how many GPH the pump would need to be?

Can't remember if Canada uses metric or imperial but 550 litres per hour is our Yanmar ysm8 spec which will be the same as the 1GM10 I'm guessing.
I still think you have a clearance or bearing issue but hey you aint the only one so it may be something else.
Yammer didnt make their pumps in that era AFAIK, they were Johnson.
Earlier boat with 6.5hp Lister & Johnson raw water pump ate impellers until I got the cover plate gasket thickness right. It didn't work with the supplied gaskets.
Please post back how you get on with your centrifugal pump. Pics would be nice too.