Are you talking about the primer lever that’s attached to the fuel adjustment needle?
Is this a similar motor?

This one is a 1946 Sea King
3.3 hp, twin opposed
Model 64EA 9008A

Mine has a “poppet valve” carb, so there is no sync. between the carb and spark advance.
The primer lever is set after you find a good running adjustment on the fuel knob, then
adjust the primer lever so it pushes down the float pin as you “richen” the motor,
turning the knob.

• This reply was modified 2 years, 6 months ago by Buccaneer.
• This reply was modified 2 years, 6 months ago by Buccaneer.

The primer lever is the piece that is attached to the fuel adjustment needle.
When set correctly, the lever pushes down the float pin, while turning the
adjustment knob counter-clockwise, forcing fuel into the carb. throat,
“priming” the engine.

To start the engine, place the magneto spark advance lever in the middle,
or a little past center, to the right, facing the engine.
Prime the motor as mentioned 5 to 10 seconds, or until you see some
gas in the carb throat. Assuming that everything is in order, it should
start after one to three pulls.

• This reply was modified 2 years, 6 months ago by Buccaneer.
• This reply was modified 2 years, 6 months ago by Buccaneer.