Topic: 1956 Johnson CD-13A – Antique Outboard Motor Club,Inc

This topic has 21 replies, 6 voices, and was last updated 1 year ago by Don.

Viewing 10 posts - 1 through 10 (of 22 total)

1 2 3 →

Author

Posts
September 24, 2025 at 10:56 am #300119
Aidan Smith
Participant
US Member
Working on a 56′ Johnson, 5.5 model number CD-13A. Not sure what the “A” means, never seen that.

The bigger issue at hand is the fact that the bottom piston is destroyed. I successfully removed it from the motor, but I haven’t taken a deep look at the bore.

Would this be worth putting a new piston in, as it is in amazing condition, or should I be looking for a replacement powerhead?

I got it this way, and with the original fuel tank.

1952 Blue Streak "B-Stock Runabout" - 1952 Mercury KG7Q
1955 Feather Craft Vagabond - 1956 Mercury Mark 55E
September 24, 2025 at 12:52 pm #300123
JACQUES
Participant
great motors if you are handy at fixing it but their should be lots of spare ph lying around. stick with inland stuff

do you have the Johnson red book bible to service it

Joining AOMCI has priviledges 🙂

1 user thanked author for this post.

Aidan Smith
September 24, 2025 at 1:31 pm #300124
Aidan Smith
Participant
US Member
Thanks,

Unfortunately, I cannot find the red book, I have been told it is on this website but it has been removed at some point.

Any recommendations on where to find it?

1952 Blue Streak "B-Stock Runabout" - 1952 Mercury KG7Q
1955 Feather Craft Vagabond - 1956 Mercury Mark 55E
September 24, 2025 at 2:25 pm #300126
elgin2
Participant
US Member
I found a white version on eBay several years ago.
September 24, 2025 at 8:38 pm #300135
JACQUES
Participant
it sells for 20$ U$ for download I frequently do post here

found it called red book but white is good

https://watercraftmanuals.com/outboard/johnson/johnson-302231.htm

just have it printed locally in 2 binders for easy reading

Joining AOMCI has priviledges 🙂
September 25, 2025 at 10:15 am #300138
Don
Participant
US Member
Adam, the important thing is to figure out why the piston got stuck to begin with. Sounds like more of an issue that just a light sticking due to sitting around. Water leak into the cylinder? Blown head gasket, sealing surfaces damaged? Leaking exhaust cover? Or, perhaps the lower seal was messed up allowing water into the powerhead.

You have the engine apart, is the crankshaft OK? If so, it is surely worth finding a used piston/rod and reassembling, if you can find new rings. You will need to check the cylinder as well. Needless to say, finding a decent used powerhead would be the simplest solution
September 25, 2025 at 11:22 am #300145
Aidan Smith
Participant
US Member
Fleetwin,

Honestly, it is difficult to tell why it seized up.

The piston, rod, and other internals are shattered into many small pieces.

The bore looks just fine, and the other piston turns just fine, but compression seems OK too.

The engine is currently back together as I had to take on another project, and needed the space.

Any ideas of what do to next in diagnosing the failure?

Thanks

1952 Blue Streak "B-Stock Runabout" - 1952 Mercury KG7Q
1955 Feather Craft Vagabond - 1956 Mercury Mark 55E
September 27, 2025 at 12:52 am #300180
Don
Participant
US Member
Did it throw a rod creating that mess? What does the crankshaft journal look like?

1 user thanked author for this post.

Aidan Smith
September 27, 2025 at 9:22 am #300187
Aidan Smith
Participant
US Member
Not 100% sure. The journal looks OK, I have attached a photo of the mess it made. It looks like the rod just exploded, I have no idea what could have caused it. The piston is not scored like it would be if there was a lack of oil, and it turns great. The other cylinder has about 95 lbs of compression.

1952 Blue Streak "B-Stock Runabout" - 1952 Mercury KG7Q
1955 Feather Craft Vagabond - 1956 Mercury Mark 55E
September 27, 2025 at 9:22 am #300188
Aidan Smith
Participant
US Member
1952 Blue Streak "B-Stock Runabout" - 1952 Mercury KG7Q
1955 Feather Craft Vagabond - 1956 Mercury Mark 55E
Author

Posts