Re: not firing all the time
Ok...primer solenoid acts like the old style choke. It enriches the fuel mix to the cylinders, and just like a choke, should only be needed when the engine is cold.
Red lever down (aligned with solenoid body) is the normal run position.
When you turn the lever manually, you open the fuel valve inside there, and allow the extra fuel to flow to the cyls.
Pressing the key in causes the valve to click, and opens the valve electrically, from up at the helm, allowing you to enrichen the mixture without having to take the hood off.
Here is my starting procedure; I have the same engine.
Engine cold. Pump primer bulb til firm. Raise fast idle lever a bit. You will have to experiment with how much to raise it for your engine. Press and hold key in... WHILE CRANKING. When engine starts, you may need to bump the key in a few more times as it may tend to stall until it warms up.
Feather down the fast idle lever as it warms up until it will run at a reliable idle.
Don't run it faster than 1500 rpm's or so. No need to race it way up there for a starting procedure.
That's how I do it.