This is what I do to keep my outboards running:
1. Use ethanol free fuel. Some marinas and gas stations sell it. But it is about $1.00 more than ethanol based gas.
2. Always, always run the carburetor dry after running at the end of the day. It only takes a day to evaporate the gas left in the bowl and if it is ethanol gas it can gum up.
3. If it won't start or runs funny or won't idle, remove the carb, disassemble, remove jets and soak overnight in a gallon can of carburetor cleaner available at any auto parts store. This has fixed about 5 engines with starting/running problems. I am hitting 1000 with this treatment.
4. Tell your congressman to repeal the ethanol mandate. It is only benefiting the corn farmers and big agribusiness like ADM.
David