Mercury 60 2-stroke...won't start

[blue92]

Ok, so here's my situation...
I've got a Mercury 60 2 stroke (I don't know what year it is, but if I had to guess, late 80's or early 90's). I've got two fuel tanks on the boat and I've been mainly running on tank #1. The boat started running slower than it normally ran (15mph vs. 26mph), so I decided to add more oil to the fuel tank... that resulted in it slowing down to 8mph.
I then decided to switch to tank #2 which hasn't been used in a while. I added a fuel/oil mix to what was already in there. Now it doesn't start.
I'm thinking there may have been bad gas or even water in tank #2. I'm a newbie when it comes to any of this stuff, so any input is appreciated.

[TAILWALKER]

I'd pull your spark plugs and check them first. Sounds like they may have carboned up and need to be cleaned with a wire brush and some gas or just replaced. If that is not the problem go get some fresh gas in the other tank.

[blue92]

I added some gas to tank #1 to even out the fuel/oil ratio, I also poured in a little SeaFoam engine treatment, and that didn't work. Then I replaced the plugs, and it still doesn't start.
Yea, I'm going to try fresh gas in one of the tanks, hopefully it works.

[TAILWALKER]

Ok, check to make sure you are getting spark. If so I'm betting it is the gas unline your gas line is bad and has a pin hole or bad connection. If all of that checks out then it is likely one of your carbs. Is it at least trying to start? Not sure if you have a manual choke or not but if not see if there is some way to choke the motor when trying to start. Also, push the throttle all the way forward and crank it and see if it will start that way.

[blue92]

So, I emptied out one of the fuel tanks and filled it with fresh gas and oil and it's still not starting. The starter turns the engine, but it doesn't fire up. I've tried it with the choke up and down and that doesn't work. It is getting spark. I'll try doing it with the throttle forward and see if that helps.

[TAILWALKER]

Unless you have a bad fuel line (primer bulb or one of the end connectors) i'd say one of your carbs is probably the culprit. Could be a stuck bowl float or low speed jet. Check your carbs visibly to see if you see any fuel leaking out of them or little drips of fuel hanging to the bottom of the bowl. Get some carb cleaner and shoot it into the butterflys of the carbs and that might help. However, if not they will likely need to be pulled down and cleaned or rebuilt.

If you are getting good spark then it sounds like your powerpacks are ok. Try it with the throttle pushed full forward and see if that at least gets it to start.