Older Johnson Powerheads

[shand]

I have a '57 5.5 hp cd-14 and would like to know if the powerhead from a similar hp model from a different year will mount up correctly with the lower unit. For example can I put a 1962 cd-19s powerhead on the 1957 lower unit.

Does anyont have exerience with the compatability amoung model years for these old johnsons?

Thanks

 

[yorab]

Re: Older Johnson Powerheads

Hello shand. You can start by going to marineengine.com and comparing the part numbers for those two blocks. They have parts diagrams going back to the mid-50's. If the part numbers are the same, then bam!, you're good to go. If they are not the same, perhaps the difference(s) is minor and the block from the '62 may still indeed work on the '57. In that case, you'll need to ask here again and hope that somebody knows the answer. But first, check if the part #s are the same.

 

[shand]

Re: Older Johnson Powerheads

So I gave it a shot and they are compatible to a degree. I bought a 1959 or later power head and it bolted right on to my 1957 lower unit. The biggest difference is that the new block has a vacuum hole for a fuel pump, different themostat set up, and water jacket. So, some parts of the 1957 powerhead are not directly compatable with the new one. Im pretty excited it worked out.

Looks like I get to make the swith to a modern gas tank!

 

[Chinewalker]

Re: Older Johnson Powerheads

How did you get the cowling to fit? The '59 powerhead has a thermostat and no cowling ears...

 

[1946Zephyr]

Re: Older Johnson Powerheads

The 5.5 compatabilty goes as follows:

1954 -55 only
1956 - 58 only
1959 on

 

[shand]

Re: Older Johnson Powerheads

The 5.5 compatabilty goes as follows:

1954 -55 only
1956 - 58 only
1959 on

With parts of the power head yes but the 1960 power head will bolt on to the lower unit of a 1957.

"How did you get the cowling to fit? The '59 powerhead has a thermostat and no cowling ears..."

The thermostat has plenty of clearance. I am either going to mill off the '57 ears on the old head and braze them to the new head or create channel to fit along the rim of the base so the cowling will slide on.