Fuel & Fuel System - Yamaha V-MAX SHO VF250 Maintenance Manual

Keeping your Machine clean
FUEL & FUEL SYSTEM
The largest source of trouble with marine engines these days lies with the
fuel and fuel system. Paying regular attention to both can help prevent major
headaches down the road. From hoses and connections to proper filtration
and even fuel additives, time spent maintaining your fuel system helps keep
you safe and your boat ready for action.
Ethanol is alcohol, and alcohol is "hygroscopic," which means it attracts water molecules. Since
nearly all boat fuel tanks are vented to the atmosphere, water can (and will) collect in your fuel.
When the concentration of water molecules in your fuel tank reaches just
½ of 1%, the water molecules will bond with the alcohol and sink to the
bottom, where your fuel pick up is. Depending on the amount of water
ingested into your outboard, this can result in everything from running
problems to catastrophic damage.
Ethanol, being alcohol, is also a powerful solvent that can loosen debris in your fuel tank and all the
tanks and lines it was in before it got to you. Once in your outboard, this debris can cause everything
from running issues to a no-start, no-run condition. That's no fun.
Scan here to learn more about
ethanol and how to combat it.*
10
What is ethanol and why is it so bad
for marine engines?
Ethanol has been added to the majority of
today's fuel supply as an oxygenate to help
reduce emissions. It's also used to extend
domestic fuel supplies.