David, whoever you got that motor from should be flogged or keel hauled! I’ve known him for 75 years and he assures me he never opened that motor.  I can verify that that motor actually did run decent in the running up tub about 14 years ago. I know he paid too much for that jewel and had to drive to Bangor to get it!

It may be of interest to you that the previous owner also states that the motor, as purchased, came with a set of dual, custom, high performance exhaust manifolds, expertly engineered and constructed and designed to breathe through two (not one!) of the finest Briggs and Stratton stubby lawn mower mufflers that money could buy (at K Mart).

And for your boating/racing enjoyment these marvels can be had at NO COST to you! The previous owner guarantees about one gazillion of a horsepower increase and just the sweetest sound!

Posting For A Friend.

Respectfully,

          Bob      

1 user thanked author for this post.

David Bartlett

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The “AB-25” superceded the “AB” and was first available in 1925 and continued to be sold as that model until the supply of built motors was exhausted.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