Yamaha F255 Outboard Rebuild Part 7: Fuel System Install

After reassembling our Yamaha F225 outboard engine, it's time to test and reinstall the fuel system. 

Watch the video above and follow the steps below to rebuild the fuel system on a Yamaha F225TXRC outboard. Use our Yamaha F225TXRC outboard parts diagrams for additional reference.

Tools and Parts – Yamaha F225 Fuel System Installation

• Ratchet and socket set
• Pliers
• Hammer
• Impact driver
• Fuel injector cleaner tool

• High pressure fuel pump filter
• High pressure fuel pump damper
• Float chamber gasket
• Fuel injector O-rings and seals
• Manifold gasket

Testing Yamaha F225TXRC Fuel Pumps

Step 1. Use an impact driver to loosen the screws from the float chamber or VST (vapor separator tank) cover and remove the cover.

Step 2. Remove the high pressure fuel pump from the float chamber cover, then connect the pump to a battery to test that it’s working properly and replace it if necessary.

NOTE: Be extremely careful when connecting the pump to the battery, as any sparks could ignite fuel vapor and start a fire.

Step 3. Remove and replace the high pressure fuel pump’s filter from the bottom of the pump, and the rubber damper from the float chamber cover that connects to the top of the fuel pump.

Step 4. Connect the low pressure fuel pump to a battery to test that it’s working properly, and replace it if necessary. 

NOTE: Be extremely careful when connecting the pump to the battery. Any sparks could ignite fuel vapor and start a fire.

Watch the clip below to see the fuel pump testing segment of our Yamaha F225TXRC fuel system video.

Replacing Yamaha F225TXRC Float Needle

Step 5. Remove the old float chamber gasket from the float chamber, and thoroughly clean the float chamber with contact/brake cleaner.

Step 6. Remove the float pin and the float itself. Remove the float needle and inspect the needle seat for pitting, corrosion or build-up, then inspect the needle’s rubber tip for wear and replace any parts if necessary.

Step 7. Thoroughly clean the float chamber cover with contact/brake cleaner, then reinstall the needle, float and float pin.

Step 8. Reinstall the high pressure fuel pump into the float chamber cover.

Step 9. Install a new float chamber gasket, and reinstall the float chamber cover onto the float chamber.

Watch the clip below to see the float valve segment of our Yamaha F225TXRC fuel system video.

Reinstalling Yamaha F225TXRC Fuel System

Step 10. Inspect all the fuel hoses for splits or cracks. 

NOTE: Worn ends of hoses can be cut off and the hose reused, but any badly worn or perished hoses must be replaced completely.

Step 11. Check that all the hose clamps are tight, and keep the hoses properly connected. 

NOTE: Replace any clamps that have become loose or badly corroded.

Step 12. Reconnect the water pipe to the cooler on the side of the float chamber, then reinstall the float chamber assembly to the motor and reconnect the fuel hoses.

Watch the clip below to see the fuel system reinstallation segment of our Yamaha F225TXRC fuel system video.

Cleaning Yamaha F225TXRC Fuel Injectors

Step 13. Remove the fuel rails from the throttle body assemblies, then remove the fuel injectors from the fuel rails.

Step 14. Attach each injector to a fuel injector cleaner tool and clean each one with carb cleaner. 

NOTE: If any of the injectors are damaged or have become too clogged up to clean properly, they must be replaced.

Step 15. Install new fuel injector O-rings and fuel injector seals onto the injectors, then reinstall the injectors onto the fuel rail.

Step 16. Reinstall the fuel rails to the throttle body assemblies.

Watch the clip below to see the fuel injector segment of our Yamaha F225TXRC fuel system video.

Reinstalling Yamaha F225TXRC Throttle Bodies

Step 17. Make sure the dowel pins are in place in the cylinder heads, then install new manifold gaskets and reinstall the throttle body assemblies to the cylinder heads.

Step 18. Reconnect all the electrical wires and cables, followed by the fuel lines and hoses and the throttle linkage.

Step 19. Remove the old seals from the intake silencer assemblies and install new ones.

Step 20. Reconnect the two intake silencer assemblies, then install them to the throttle body assemblies.

Step 21. Reinstall the flywheel cover to the top of the motor and you’re done.

Watch the clip below to see the intake installation segment of our Yamaha F225TXRC fuel system video.