Re: 9.9 Johnson Carb Question

[David Stanton]

Thanks for the tips!
This is not a salt water motor, and it’s not overheating.
My friend just bought this and was told it hadn’t been run for many years, so past running history is unknown.

I totally missed in the diagram that the carb has a bearing on the low speed needle – never heard of that before – I’ll check that. Is this something I can see with a bright flashlight looking in when I remove the needle? or "feel" poking a stiff wire with a small bend on the end in there? if not, how do I check for it?

I’ll check compression too.

I’ve never removed any of those lead shot plugs either and hope I don’t have to

Here’s a thought that came to me last night – I’m wondering if it’s possible that at slow idle, one cylinder is dropping out, maybe from a week coil or corroded coil ground connection? There is visible rust/corrosion the bolt at the top of the upper coil and that has ground wires, etc under it. I had it running first in a barrel, then when I put it on a boat, the fast idle "seemed" good but it was runnin’ on one cylinder when I went to WOT. After running a couple minutes, I dropped to an idle again and back to the dock. I shut it off briefly and then took it out again and both cylinders kicked in and WOT was great,and fast idle improved also. I’m thinking maybe the corroded ground connection got "flexed" as the motor heated up and metal expanded, squeezing/flexing connections to the block making for a better ground and that may have activated the 2nd cylinder. I’m thinking maybe at a slow idle, the ground still isn’t good enough, and that cylinder kicks out? I’ve never heard of this before, and it sounds a bit far out, but I’ll take apart and clean up the ground corrosion under that bolt and see if it helps.
Dave