i have a full tank of 2 stroke fuel/oil that has been sitting for about 3-3.5 months.

i just got the boat back in working order and i dont want to have to deal with bad gas/carb problems.

i did not have any stablizer in the fuel. should i dump it or is this fuel ok?

I will never run fuel that's over a month old in mine,  Fuel will loose octane very quickly.  You will have some say they've left it in for months and ran it with no problem but not me, I've seen too many times what bad fuel does to a motor.  However, if you have oil injection and bad fuel damages the motor, you can always blame it on the oil injecton.  That's what gets blamed about 90% of the time anyway.

What I will do on 87 octan motors that has only set for a couple of months is pull about half the fuel out of the tank and fill it back up with 91/93 octane.  When that is gone, pour the other half in and top it off again with high octane.   After it's three months old, I pretty much consider it lawn mower gas, even if it had stabalizer in it.  I just don't take chances and try to run old gas, it can bite you big time.

I agree with W2S, better safe then sorry. Marine engines are waaay to expensive to have worked on.

Most marine shops charge 70-80 per hr for labor.  That will buy a lot of gas.