This ol' Johnson

[Myfirstjohnson]

A couple of you know my story. And the saga returns. Motor runs boat plains. Goes about 20. And after about 2 minutes or so. Boat bogs down like you just hit the choke. When I idle all the way down.... Runs fine. Up idle runs fine. Up aliitle bit more BOG!! 1976 Johnson 35.
Came home looked everything over. Pulled plugs. Look good.
Next day. Starts, runs, drives, planes about 2 minutes later bogs again.

1. It's gotta be something that is changing when the operating temperature is reached.

2. It's sounds fuel related? Doesn't it.

3. It will idle all day long even a plowing fast idle. Just doesn't like being warm crazy Johnson

 

[jbjennings]

Re: This ol' Johnson

If it idles fine, try pulling one of the plug wires. If pulling one kills the motor, but pulling the other does nothing, then you're not losing spark and the ignition system is fine. Of course, DON'T pull it with your hand or it will shock the pee out of you. Use some insulated pliers or such. It sounds like you have a weak fuel pump, or a float that is adjusted too low and not letting the fuel bowl fill. Try pumping the primer bulb when it bogs. If it picks up, then the fuel pump is suspect.

 

[kfa4303]

Re: This ol' Johnson

+1. If it doesn't like running warm, that makes me think it may be an electrical/ignition issue too. I would check for strong spark on both cylinders after you get it to fail. Of course a good carb cleaning never hurts either.