Yamaha V-MAX SHO VF250 Maintenance Manual page 12

Are there any other fuel filters, and where are they located?
Your Yamaha outboard has a system of fuel filters on the engine, as well. It's important to know
the location of these filters and to clean or replace them at the recommended intervals. You can
find this information in your service manual or through your authorized Yamaha Marine dealer.
As an example, here's a general guide using a modern Yamaha fuel-injected four stroke.
1
Primary On-Engine Filter.
•
and is usually made of plastic you can see through. It filters fuel coming into the outboard.
This "primary" filter usually features a small water trap at the bottom of the cup. This
is the first filter after the 10-micron filter; so if there's water in here, it's time to change
your 10-micron. On Yamaha outboards, there may be a red ring visible inside this filter.
Don't ever remove it. If it's floating, you've got water in this filter's trap. Time for a change.
2
• Vapor Separator Tank (VST) Filter.
Separator Tank (VST), this filters gas again just before it's pressurized into the fuel injection
rail(s). The VST is a prime spot in your fuel system where deposits and gum can form,
particularly if fuel is untreated, and the VST filter is the most difficult to access and usually
the most expensive to replace. Help protect it by consistently treating every tank of fuel, and
regularly inspecting and servicing the first two filters in the fuel line.
3
• In-Line Filter.
VST (vapor separator tank) and/or in the fuel line between the VST and the fuel rail, located
along the top of the outboard. Refer to your service manual or contact your dealer for the
exact location for your model.
4
Fuel Injector Screen.
•
and are not user-serviceable. If debris somehow makes it here, the fuel injectors must be
removed and professionally cleaned, or replaced—reason enough to inspect and/or change
your fuel filters regularly.
FUEL FILTER
COMPARISON
YAMAHA
FUEL/WATER SEPARATING FILTER
10-micron filtration
at 95% nominal
efficiency
Tall filter element
cleans 90 gallons
per hour
Sealed metal
bottom
Large water
reservoir
Sealed can
12
This is typically on the front, side, or rear of the powerhead,
Attached to the electric fuel pump in the Vapor
Some models have an in-line filter between the primary fuel pump and the
These are built into each fuel injector. They're very fine-mesh screens
AFTERMARKET
FUEL FILTER
Shorter filter element
Plastic base
Screw-on bottom