Reply To: 1955 Johnson RD-17

[Don]

Does the engine knock when you run it? Generally, you will hear a knock at dead idle, but it will go away when you advance the throttle if slop is an issue. I know you said it runs a little rough, but does it knock? Sometimes powerheads will have a little “clunk” when rotating past TDC to with no plugs installed…You can always use a little wooden dowel to check for wrist pin/rod slop. Simply rotate one piston about half way up its compression stroke, then back the flywheel off slightly. Now, used the dowel to attempt to push the piston back down, you will feel some sliop and hear a clunk if there is wrist pin/rod wear… Repeat this process with the other piston….
I just don’t want you to condemn this engine needlessly….D