18 hp long or short

[BPULASKI]

Have determined my johnson 1s a 1961 model fd15f how do i determine wether it is a short or long shaft from the model number. I also, have sn#2216514

 

[Joe Reeves]

Re: 18 hp long or short

1961 18hp Johnson

It doesn't matter what the model number states as the engine can be changed from a short shaft model to a long shaft model quite easily.

Measure from the underside of the transom bracket (the portion that would be sitting on top of the transom) down to the cavitation plate just above the propeller.

Somewhere around 15" = Short shaft

Somewhere around 20" = Long shaft

 

[kfa4303]

Re: 18 hp long or short

+1. Most OMC motors of this era had sort of an odd leg length of around 18", which is longer than the standard 15" short shaft, but shorter than the 20" long shaft. As a result, they tend to drag a bit on a standard 15" transom. You want the anti-vent plate, found just above the prop, to be level, or slightly higher than the keel of the boat. I had the same problem with my '66 20 hp, and ended up building a little bolt-on transom riser to get the motor to the right height, it also reduces the draft a bit. Here's a great link.

http://www.leeroysramblings.com/johnson_E-FD_15_18hp.html

 

[Chinewalker]

Re: 18 hp long or short

If it is a long shaft, it will have a 5-inch extension bolted between the exhaust housing and the gearcase housing. No extension - short shaft...

 

[82rude]

Re: 18 hp long or short

If it is a long shaft, it will have a 5-inch extension bolted between the exhaust housing and the gearcase housing. No extension - short shaft...

ditto.

 

[tanuki]

Re: 18 hp long or short