The previous owner had it running like a top when I picked it up. No hesitation. Went into and out of gear seamlessly. Idled like a dream. Said he slow idled with it for hours in the fall trolling for walleyes, and I believe him. Maybe I'm a sucker, but he's answered every text I've sent to him and tried helping me troubleshoot things. If it was a melon, I have a feeling he'd just ignore me.
To address some of the questions:
1) New fuel as of June mixed at a 50:1 ratio.
2) New fuel line and primer bulb as of about a month ago.
3) New spark plugs. That initially was what I thought was a problem, because the bottom cylinder was wet and the plug seemed pretty corroded. Replacing the plugs seemed to help, but apparently didn't fix the main issue/s.
4) The gas tank is internal and doesn't have a vent on the cap, however maybe the vent tube is plugged. I'll check.
5) Yes, on land I put it in gear and the prop spins.
I really think maybe I didn't hook the fuel lines up the best. They slid on just fine, but I had an awful time trying to cinch the zip ties tight. It could be they're still loose.
Again, before I touched the carbs, I had no problem running the motor at full steam. It even went down pretty close to idle without stalling. If I got too close or went to neutral, it would sputter dead within a few seconds.
Actually, there was ONE time where I motored across the lake and got to the spot and put it into neutral and it idled like nothing was a matter. I just sat and stared at the motor for 20 seconds as it just chugged along. Then we fished and I tried starting it again and apparently the Germlins were off their union break.