I have twin 5.7 mercuisers. I did not use them last year. There was
about 60gal of 18month old gas in it. I added watersorb a few times
last year. When dewinterizing it this year I added an octane booster
and topped it of with 60gal of fresh 89 gas. I also added the Penzoil
marine fuel system cleaner. I changed all fuel filters and water
seperation filters. Both engines will start and run but there still
appears to be a fuel issue. Port engine seems to run fine but will
stall when idling/no wake. Starboard engine has problems out of the
hole. It sounds like it is not getting enough gas.

Both engines ran fine when I closed it down for the 2003 season. It
seems to be the carb's on both engines. Is there a way to clean them
properly or may they need to be rebuilt or purchase rebuilt ones?

thanks in advance.