uneven running during aceleration

I am about to buy a Glastron 17" with a 1991 mod Yamaha 130 hp. I was informed that it had uneven running during aceleration, but on idle and when pick up the speed it was running smoothly. Do you have any advice regarding this. Would this be a big problem for me?
Looking forward to your advice.

[boats.net]

I would suggest getting it checked out, compression test, ignition test to see if it has any major problems.

The engine has not been used for some time, could it be that easy to just check and clean for dirt in the carborators, change fuel filter and change the spark plugs?
A new velded fuel tank has been installed to it, so can deposits/ dirt from the installation make the uneven running? Or is it really likely to be problems with the ignition units?