Re: Early Johnson Waterbug? Model A? Model AB?

[PM T2]

saw your photos in the first post you did, they showed up there.

Larger "intakes" I think you have that term confused, do you mean "exhaust manifolds" because these motors don’t really have an "intake" per se, just a cast neck on the front of the crankcase, and those are mostly all the same.

Yours does have the later A-25 foot on it where the lower unit housing brace arm connects to the anti-cavitaion plate, whereas the earlier Johnson lower unit used a plate that was separate (and optional) and the brace was independent of the anti-cavitaion plate.

Check the underside of the crankcase where the cylinders bolt up to it and see if you find a serial number stamped in there. That number is supposed to match the one on the rope sheave.

IF – and I say "if"- the serial number on your motor is genuine, then it would would have been a Model B built in 1923. The "B" was a salt-water motor versoin of the Light Twin model "A", but it did not have a brass lower unit. It would have had corrosion materials used for the driveshaft, propshaft, and possibly the gears (not certain about that tho).

It may be possible that you’ve got a 1923 motor that received a later lower unit as a retrofit to replace a worn-out or damaged original foot.

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...