115hp runs at half choke

I have a 115hp yamaha (20 years old) that will not get up to speed under a load unless the manual choke is pulled out some. When I pull the choke out a little motor runs just like it should. Had the carbs cleaned in the fall of last year and mechanic said it was pretty bad. After the carbs were cleaned it ran fine but now I am having trouble. It also is hard to start and takes a while to clean up. I have tried putting sea foam & octane boost in the tank and that seemed to help a little. Is it possible I have some debris in the jets??? I have put new plugs in and they look fine.

Thanks for any input you can give me.
Steve

[jb123]

yes carbs need to be cleaned again...anytime they set up for a month or more, or get water or debris in gas/tank they will need to be serviced.