4hp losing power in one cylinder

Bought an old Johnson 4hp 2 stroke outboard. I've looked all over and can't find a model number or nameplate.

When I first got it, it ran great. Within a few weeks, it started to get hard to start and I had to use ether to get it to start up. But once it started up, it ran great.

A few days ago it started to feel like it was stumbling. Feels like it's only firing on one cylinder. It'll run like that for a minute or two and then the second cylinder will kick in and it'll run on both cylinders for 30 second to a couple minutes and then one cylinder will die. And it'll run at half speed for a few seconds or a few minutes. Back and forth.

I use this motor everyday to get back and forth to my boat and, at full speed it takes me 7 or 8 minutes each way.

I'm going to change the plugs today but I'm wondering if it might be something else? On the front of the outboard, there is a low speed and high speed adjustment. I haven't paid much attention to these but I'm about 99% sure these have vibrated out of position. Can anyone point me to info on adjusting these settings? Thanks

They aren't rocket science. Tweak them to where it runs the best at full throttle and idle speed.

If plugs don't fix it, you probably need to go into the ignition system. We have to know what you are working on for any more info. Post a picture.

Welcome. There is a good chance your loosing spark to one cylinder. I'd probably do a spark jump test. Take out both plugs and rig something up directly to the plug wire to see if you can get a nice blue/white spark that will jump 1/4 to 5/16". If a cylinder is weak, then pull flywheel and report back with what you find.

When I changed the plugs, I noticed the top plug was wet and dark while the bottom plug was dry and tan. I figured the top cylinder is the one causing problems. I pulled the wire from the plug, put the better of the two old plugs into the wire and carefully held it against a head bolt. I pulled the starter cord maybe 10 times. I only saw it spark up once. So I'm guessing the issue is electrical on the top cylinder. I'll post some pictures of the outboard. Maybe you guys can help me determine which model I have so I know how to proceed.

I couldn't figure out how to post pictures so I uploaded pictures to imgur. Here's a link

https://imgur.com/a/2rrFbKL

Nice motor. Gotta pull the flywheel. Examine the coils for cracks or a hole arcing to ground, (sometimes underneath). Examine wires for any damage. Then look closely at the breaker points, if they are pitted, you should replace them.