01 Yamaha 225 EFI getting flooded with fuel. PLEASE HELP, my mechanic is lost.

[clctrader]

I currently own a 2001 Yamaha 225HP EFI. Bought the motor a while back (3 months ago) just checked compression but never started it. Just finished my project boat now and I got it started. It gets flooded with fuel. Starts right up but idling rough like its on 3 pistons due to fuel flodding the spark plugs.

I removed the 3 diaphragm pumps to check for leaks but found none. I removed the fuel rail with injectors and when I prime the bulb fuel comes rushing out of the bottom intake hole.

Where is this fuel coming from ???? Isnt fuel supposed to come ONLY from the injectors? I am lost. Please help Is there something connected wrong in this motor?

 

[PBJohn]

Re: 01 Yamaha 225 EFI getting flooded with fuel. PLEASE HELP, my mechanic is lost.

Check the float operation in the VST. There should be a vent hose that comes off the top of that tank that plugs into the intake.

 

[rodbolt]

Re: 01 Yamaha 225 EFI getting flooded with fuel. PLEASE HELP, my mechanic is lost.

what PBJohn says, its either a leaking VST needle or a blown fuel pressure regulator.