I spent the last hour reading the Antique Outboarder archives on Johnson
PO articles from the 1970’s. I took some notes for future reference,
seeing how I’ve never had or ran a PO.
General Information-
Check flywheel torque occasionally, they have a habit of losening?
Spark Plugs- Champion R-7 (replacement D9J)
Points – .020
Piston Rings part number is 29-10, still available from OMC in 1973
Low speed jet plugs easy, inline filter recommended
3/4 pt / gallon oil to fuel mixture recommended, or more for heavy use
Gear Lube- Texaco 950 (thick, black, water proof)
Fill from bottom, in hole marked "grease" until it comes out the hole marked "vent", which is above the cavitation plate. (An inspection hole plug is below the cavitation plate.) The hole marked "Drain" is a water drain.
There is another plug, just above where the lower unit foot attaches to the drive shaft housing. If labeled, it will be marked "Drain", but it’s a drain for excess fuel that passes the lower engine bearing. It should be drained every 5 to 10 hours of running.
Starting – High Speed Needle 3/4 turn open, Low speed needle 1/2 turn open
Mag lever 1 or 2 notches right of center
Set choke all the way closed on full choke models *
Close throttle
Open compression release
Rock flywheel (with rope) about 10 times, (to charge cylinders with fuel) then pull through to start
When started, go to 1/4 choke or so
Close compression release (all the way to left)
Don’t open throttle until warmed up a little bit
Adjust high and low speed needles as needed
*On the earlier PO-15’s with the cut-away choke carburetor, you can prime engine by pushing down the float pin, and may not even have to use the choke.
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