"Guys, you should start new di
"Guys, you should start new discussions - your questions will get lost in the pile of threads here.
Donald, you have an 88 model, built by Yamaha. Is the oil system still there? it would have be a system called autoblend - tank remote to the engine itself - fuel line goes to the oil tank then fuel line from oil tank up to the engine. If that's your set-up, rip it out and start mixing your gas at 50:1 - Autoblend was a nightmare that killed more motors than any other single cause.
Any motor that is "new to you" should be gone over completely - the smoke and the stalling could be caused by clogs in the carb - but start with the basics.
Check the compression/spark at all cylinders - replace the plugs, lower unit oil and the impeller (unless you have proof that it was done "this year") - then start troubleshooting.
Used Boat dude - that is a 1984 Yamaha built "C" model mariner.
Selecting a prop requires a fair bit of information - there is no "one size fits all answer" - it must be specifically matched to your rig and how you use it.
Would suggest the following - either start a new discussion and can ask you for some details, or click my name (to the left) and drop me an email. I have a prop calculator which can give you a recommendation specific to your application - just needs some info..."