1964 4v 75hp Johnson no idle

Good Morning all,
I have a 1964 Johnson 75 hp v4 motor, it may have a total of 50 hours on the motor. We pulled it out of storage this summer. I have cleaned the carbs put on a new impeller and cleaned the plugs and points along with some other minor maintenance.
We put it in the water last night for a full test run. It started fine. But when you lift the start lever it idles very low and stalls out. If you put into gear while the start lever is down it will go and goes into full throttle but it is very sluggish. When you come back down it will stall at low idle. It will start again with out much trouble.
While cleaning things up I took off the fuel pump and made sure that the gaskets we not stiff and rotted. The only other issue is with the fuel line. When priming it the bulb gets stiff but as we are running the motor it is soft again.
I thank you in advance for any help you can provide.
Have a great day

Re: 1964 4v 75hp Johnson no idle

Sounds like it is not running on all four cylinders. Several possible reasons why.

The primer normally goes soft when the motor is running. That is because the conditions inside changes from pressure (you squeezing) to suction (fuel pump sucking gas from tank). Disclaimer: "Soft" does not mean "collapsed"--that is a different story.

Re: 1964 4v 75hp Johnson no idle

Thank you for you help. I have some reason to believe that I am firing on all 4. During a "tank" test I removed the plugs and had excessive carbon build up. I cleaned the plugs ran it in the water and had wet plugs in 3 and 4. made additional adjustments and now getting dry plugs with a light tan tip. Not quite the roasted marshmellow that I would like to see.
Will old plugs cause these issues? I intend to change them after I have the carbs running smooth.
I am also not getting a response from the low idle adjust. Meaning while adjusting them they will not change the speed of the engine.