87 Johnson 20HP with hard starting and rough running problems

[Thaddeus Severy]

Hi! Any help would be greatly appreciated as I have a few questions. First a short description: 1987 Johnson 20HP w/electric start. Will not start on idle, only with ?+ on the throttle handle. Will not idle after start. It runs ok but not great, and is rough running on top end until it appears to clean itself out. Then restarting can be difficult.

What are the initial carburetor settings? (I found the jet screw on top of the carb, with the black knob, turned out 19 ? turns)
Throttle cable settings (if any)?
How exactly does this style of electric choke work? --- with the small gas lines going to the bowl and flange mount of carb body and back to the cylinder head and the red colored valve handle?

Moreover, as anyone experienced these symptoms and if so, what did you do to correct them?

Thanks for any ideas folks, I really appreciate the help

Thaddeus

 

[fireman57]

Re: 87 Johnson 20HP with hard starting and rough running problems

The black cylinder with the red lever is a primer solenoid. It is activated electrically and shoots fuel into your engine. Replaces a choke. The red lever can be turned one way for manual operation and the other way for auto. I would be the reason the adjustments were changed is because the lever was set to manual and your engine was flooding so they tried to adjust the carb to compensate for it. Try the lever in the other position and do a search at the top rigth of the page for your initial carb settings.