At a loss and looking for some help with a 1985 Johnson 9.9 having starting and idle issues after winter storage

[crackerjackjack]

I recently took out the motor after its winter storage and faced trouble starting it. Initially, it wouldn't start at all. However, after spraying some carb cleaner into the carburetor, it did start but had an unstable idle. After letting it sit for about 30 minutes, it wouldn’t start again. The engine worked like a charm last summer (started in one pull), but now it's proving to be quite problematic.

Here's what I've tried so far:

1. Changed the spark plugs. Unfortunately, they only had the sustained high-speed fixed gap ones in stock. Still, the issue persists with both the old and new plugs.
2. Filled it with fresh gas and added Sea Foam.
3. Replaced the fuel pump.
4. Rebuilt the carburetor using a kit. The bowl inside wasn't perfectly clean; there was some staining/residue. I sprayed all the holes with carb cleaner and replaced the gaskets.
5. I forgot to note the high-speed idle screw position. But after consulting the service manual, I carefully turned the screw in until it seated, and then turned it out between 3/4 and 1 turn as an initial setting.

After these steps, the engine did start and seemed to run and idle better. But then, it would die after about 5-10 minutes of idling. It sounds like it’s running out of fuel (i.e., it doesn't choke itself when idling but gradually loses revs and turns off).

Here are some observations:

1. I spotted air bubbles in the fuel line.
2. The fuel line was only filled up to the fuel pump after priming. When the engine died, no fuel was visible in the line leading to the pump.
3. As it starts to fade (at WOT idle), pulling the choke gives it a brief resurgence for about 20 seconds. But it eventually dies, regardless of the choke's position.
4. When putting the carb back on one of the bolts seemed stripped a bit on the end. I was able to get the nut on and tighten it to where the carb seems very secure and doesn't have any play, but the nut still kinda spins with force.

I'm at a loss here. Does anyone have suggestions on what might be causing this?

 

[jimmbo]

Welcome to iboats

Bubbles in the Fuel Line, indicate a Leak, allowing Air in. Eventually the Carb is starved for fuel and the engine croaks
WOT Idle? What exactly do you mean by that?

 

[crackerjackjack]

Welcome to iboats

Bubbles in the Fuel Line, indicate a Leak, allowing Air in. Eventually the Carb is starved for fuel and the engine croaks
WOT Idle? What exactly do you mean by that?

Do you think I need to replace the clear fuel line? I didn't think it was that becuase when I do prime it, the bulb gets hard and there isn't gas leaking out anywhere.

Regarding WOT, I meant high-speed idle. I basically have to turn the throttle to full to start it and then I turn it down to the lowest position.