How to BS Swap a Johnson! Outboard Motor Swap - 19hp Briggs & Stratton on 20hp Johnson Lower Unit

A special guest shows his latest creation! A 1973 20hp Johnson outboard motor given new life with a brand new 19hp Briggs & Stratton motor swapped into place of the old engine that died from a worn cylinder causing low compression. A water cooled to air cooled conversion! You've heard of the LS swap but have you heard of the BS swap?

[@dannycarter725]

One of the best conversions I have seen. Thanks.

[@billslack1879]

a very thoughtfull conversion!

[@ct1762]

but at 3000 rpm what kind of prop did you find? the biggest pitch is around 12'' for those small gearcases. that 20hp originally put out about 15-17hp at the prop so this 19 is about the same is guess. must make a racket being air cooled!

[@jesseg6708]

Put it on the water

[@jeffmckaig4763]

Really interesting job on this, haven't seen a conversion quite like this, Congrats on your project, was wondering how fast does the motor push your boat now.Thanks for sharing and posting. I have one of the 5hp Briggs and Stratton outboards, refurbished it and really enjoy it, but still thinking about more HP options... Happy Motoring and fishing !

[@squareBgarage557]

Thanks for response. The speed is very good. One problem I had was that the governor had to be manipulated to get the maximum speed from it. This was a new motor, an older one might have been easier to adjust. At first it was slow like a lawnmower. I put an auxiliary throttle control on governor linkage and now it moves a deep sided 14' very well.

[@samuelmcgill-rl3lb]

i cant see why anybody mounts a gas tank above a motor when chinese electric fuel pumps are 5 to 10 bucks , great build ,happy trails .

[@fathaar]

Because gravity never fails, but 5 to 10 dollar chineese electric fuel pumps do