Reply To: 1927 Johnson AB-25

[PM T2]

Tubs, the way it was explained to me by Bob Zipps is that the salt water motor models were as follows; The “B” begat the “BN” which begat the “AB” which begat the “AB-25”.

The original was the “B” and it had no bronze exterior parts other than the usual water pump. It was only touted as having corrosion resistant internal parts like the shafts and such.

The “BN” was released in 1923 and was the successor to the “B”. It was also the first Johnson motor to have a brass lower unit and basically bronze exterior parts from the transom bracket on down. All “BN” motor serial numbers that I’ve ever found conform to the 1923-24 model years.

The “AB” was apparently an evolved form of the “BN” and was available for a short time only, in late 1924 only as I recall. it may have been very briefly available in 1925 but all the “AB” serial numbers I have seen conform to the 1924 model year. Rick Eichrodt had a model AB in his collection, and I’ve only heard of a couple of others that have been found with that model designation,

The “AB-25” superceded the “AB” and was first available in 1925 and continued to be sold as that model until the supply of built motors was exhausted. Again, the only “AB-25” serial numbers that I know of conform to the 1925-26 model years.

Funny thing about the “BN” is that the model designation was just stamped somewhat haphazardly onto the rope sheave but not in the curved pad area where the model info typically got stamped. It’s almost like stamping the model on the rope sheave was an afterthought and done in a hurry. I won’t speculate as to why they look that way, I just know all the BN’s I’ve ever had or have seen are stamped the same way.

Hope this helps.
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...