1993 Johnson 120 rough idle

[Bowkill]

I have a 120 johnson I've been beating my brains out over. Model j120tletf. It starts easy, runs great on top end. I had it out a week ago and pulled two teens on two tubes with no problem. But docking and loading is a pain. What I've done in the last year: new timing base, new cdi box. New plugs, carbs rebuilt, new intake manifold gaskets, new fuel filter, and primer bulb. All done by a dealer. ( let's not discuss money spent) sometimes it will idle in the water in gear for several minutes, but other times it coughs/sneezes until it stalls. Compression good on all four. Any direction as to what I need to check would be appreciated. I've checked all recirc hoses, check valves, and fuel lines. I almost think the cold start is coming on for no reason. Is there any way to check it for sure?

 

[Bowkill]

Update. I found a few potential issues today. A few crappy connections on the cdi, and a crack in the primer solenoid cap. I do have another question. There are 4 hoses running to the crankcase. Three of them you can take them off the crankcase and suck air(and a little fuel) but you can't blow back to the carb, but the bottom hose on the starboard side you can't suck air from the T check valve but you can blow through it. I don't know why it would be different. Also can you check te timing with an automotive timing light or do you have to use a marine unit that plugs into the power pack???