Reply To: 1924 Johnson A water pump

[PM T2]

FWIW – the cylinders are different between the “A” and the “A-25” but they can be interchanged, as demonstrated here.

https://www.youtube.com/watch?v=REnCyf-_SoA

The differences are that the A-25 cylinder has a wider intake runner than the “A”, and also the “A-25” cylinder has a wall extension that protrudes into the crankcase whereas the “A” cylinder wall is flush with the gasket surface.

You can use the “A” pistons in an “A-25” cylinder, but not the other way around because the “A-25” piston has a longer skirt and a third ring at the bottom edge.

Another FWIW – I’ve repaired far more serious cracks than what you have, I used JB Weld to fill in the voids after I used a hand grinder to vee out ditches around the cracks. See attached images.

Hope this helps.
Best,
PM T2

He's livin' in his own private Idaho..... I hope to go out quietly in my sleep, like my grand-dad did..... and not screaming, like the passengers in his car...