compression readings 1955 Johnson 5.5 CD-12

[Mr.Stuart]

I posted this in another thread but with the amount of posting going in here right now, it's not going to take long for that other thread to be out of sight and out of mind, so I'll ask here.

I did a compression test on my old 1955 Johnson seahorse 5.5 (CD-12)
I got 80 pounds compression per cylinder

I think that's acceptable, but thought I would ask anyway.

 

[lindy46]

Re: compression readings 1955 Johnson 5.5 CD-12

Good readings for that motor - should run great.

 

[mchin]

Re: compression readings 1955 Johnson 5.5 CD-12

On my classic evinrude/jonhsons, anything about 60+ works fine, just as long as both cylinders are within 10% of each other. So at 80, you're sitting pretty.

 

[jonesg]

Re: compression readings 1955 Johnson 5.5 CD-12

I'll swap PSi if you don't like 80,
I get 70 in each, 1959 10 hp.

 

[samo_ott]

Re: compression readings 1955 Johnson 5.5 CD-12

80's good. Id be very happy with that.

 

[Mr.Stuart]

Re: compression readings 1955 Johnson 5.5 CD-12

Ok, thanks for the input, I thought it was ok to, but figured I'd ask, with out a service manual (looking for one now) I don't know what the exact specs are supposed to be.

I'm going to go through the motor, but before I did I figured I should be checking to see what the compression was like, and when I tested it, I got 80 on each cylinder, so I?m guessing it?s going to be worth putting a little money into to get it running.

As soon as I can collect some parts for it, I'll go through it and get it running, I would really like to find a cheap parts manual for it though, the only ones I've found so far are selling for something like 30 or 40 bucks and I think that's outrageous pricing, but then again ......I'm cheap, so I?m always looking for a bargain, but who isn?t?

 

[samo_ott]

Re: compression readings 1955 Johnson 5.5 CD-12

As I mentioned in your other thread, I have the '54 and the '56 5.5's parts manuals on pdf if you want to pm me with your email address.

 

[wbeaton]

Re: compression readings 1955 Johnson 5.5 CD-12

As I mentioned in your other thread, I have the '54 and the '56 5.5's parts manuals on pdf if you want to pm me with your email address.

Take the 1954 CD-10 manual. It is pretty much identical to the 1955 CD-11.

The compression specs were never published so even a factory manual won't have them.

 

[Mr.Stuart]

Re: compression readings 1955 Johnson 5.5 CD-12

Take the 1954 CD-10 manual. It is pretty much identical to the 1955 CD-11.

The compression specs were never published so even a factory manual won't have them.

thanks for the info, I got the 54 manual, and found the part numbers I'll be looking for.

thanks Steve for helping me out, I'll get some good use out of that manual.

from what I've gathered reading here, the 80 pounds of compression I have on this motor are good readings, so it will be worth fixing.

I'm shopping around for parts now, I'll get some more pictures up here when I get a chance, the family has other plans for me today, so I won't be doing any outboard work today.

Stuart