1947 Johnson HD 25

[Jthieb]

looking for a service manual

 

[F_R]

Are you the guy that asked for the same thing at the aomci.org site? The answer doesn't come any better than what you got there.

 

[brodmann]

Those old motors just require a screwdriver and a pair of pliers to repair!! What specifically are you trying to do? There's old-timers here that I'm sure can answer specific questions. I've often found repair manuals for older motors in the reference section of my local public library. Might want to check that out. Many have been put on micro fiche or on computers.

 

[Crosbyman]

the Johnson service manual suggested should answer most questions available free or 20$ . ..aside from taking the engine apart most issues related to ignition & carburation are explained and/or applicable to generations of engines until you reach fancy electronics and ECU/EMM controls of modern engines.

that is the beauty of oldys.... they can be fixed cheap and still run for years for the less than the price of taxes on a new motor. .

 

[TN-25]

Watch for excessive clearance on the bearings. For a bronze bushed motor, especially a rotary-valve type such as the HD it relegates it to display purposes. It'll never run right if worn out, and since they are hand-reamed, they don't have the possibility of replaceable bearing inserts to restore clearance.

 

[jimmbo]

Don't forget, you have run a 16:1 Oil Mix, Regardless of the Oil being Modern TCW-3. Post #5 sums up the Reason