Yamaha F25 - Nothing But Issues

[LCWhaling]

I bought my first boat in June and it came with a 2017 25HP Yamaha outboard. The motor was running fine until water got in the fuel (with less than an hour of my time on it) and I had to spend $$$ for a mechanic to flush out the entire fuel system (VST tank, high pressure fuel pump, etc) along with some maintenance the prior owner had failed to do.

I now have a fuel water separator and a lighter wallet, but the motor will only run for ~8 minutes before dying with fuel starvation symptoms (e.g. bulb goes soft but I can sometimes squeeze it aggressively to save the motor from dying). A new low pressure fuel pump didn't help. The mechanic now thinks the high pressure fuel pump is losing voltage and he's waiting on a part.

Two questions:
1. Does this seem like a plausible point of failure for a 6 y/o motor with a couple hundred hours?
2. Am I just incredibly unlucky or is this the usual welcome to boat ownership? I've had the thing for 6 months, enjoyed less than an hour of use out of it, and paid the entire market value of the motor in mechanics fees. Started shopping for new motors...

[99yam40]

it is simple to monitor voltage to see if it is going away, as the motor dies.
it is simple to drain the VST when it dies to see if the VST is low on fuel.
troubleshooting is needed

[ausnoelm]

If the primer bulb goes flat, you have a restriction between the bulb and the tank air vent. Make sure the tank vent is open and clear, make sure the fuel line is not kinked, make sure the new filter is installed correctly (inlet and outlet) make sure the tank pickup is clean.

[LCWhaling]

Thanks for the replies.

Yes, the mechanic confirmed the fuel pump is losing voltage.

Regarding fuel, I replaced the filter (fuel and fuel/water) and lines from the tank to the motor. I also tried an alternate tank.

[99yam40]

Thanks for the replies.

Yes, the mechanic confirmed the fuel pump is losing voltage.

Regarding fuel, I replaced the filter (fuel and fuel/water) and lines from the tank to the motor. I also tried an alternate tank.

is that the pump in the VST that loses voltage?
I am fairly sure that pump should have voltage to it at all times while the key is turned to the on position.
the ECU will open and close the neg to make the pump run when it wants it to

[LCWhaling]

is that the pump in the VST that loses voltage?
I am fairly sure that pump should have voltage to it at all times while the key is turned to the on position.
the ECU will open and close the neg to make the pump run when it wants it to

My model has a tiller with manual start, so there’s no key (or battery). As far as which pump is losing voltage, the mechanic simply told me it’s the high pressure pump (low pressure pump is purely mechanical and I just replaced it). If there are two high pressure pumps, I don’t know which is malfunctioning.

[fairdeal]

Is your engine manual start or electric start?

Do you know what part the mechanic is waiting on?

[99yam40]

My model has a tiller with manual start, so there’s no key (or battery). As far as which pump is losing voltage, the mechanic simply told me it’s the high pressure pump (low pressure pump is purely mechanical and I just replaced it). If there are two high pressure pumps, I don’t know which is malfunctioning.

since it is a manual start and no battery, I guess the voltage comes from the lighting coil and rectifier/regulator.
is there an on off switch on the tiller handle?
Or just a push button to kill the motor?

maybe there is a bad connection somewhere.
strange it will start and run 8 minuets and then die

[boscoe99]

My model has a tiller with manual start, so there’s no key (or battery). As far as which pump is losing voltage, the mechanic simply told me it’s the high pressure pump (low pressure pump is purely mechanical and I just replaced it). If there are two high pressure pumps, I don’t know which is malfunctioning.

Do you not have the complete model identity on a placard on the side of the motor? They are not all the same.

[boscoe99]

since it is a manual start and no battery, I guess the voltage comes from the lighting coil and rectifier/regulator.
is there an on off switch on the tiller handle?
Or just a push button to kill the motor?

maybe there is a bad connection somewhere.
strange it will start and run 8 minuets and then die

If the motor is the model of which I am guessing, there is only the kill switch.

[boscoe99]

I bought my first boat in June and it came with a 2017 25HP Yamaha outboard. The motor was running fine until water got in the fuel (with less than an hour of my time on it) and I had to spend $$$ for a mechanic to flush out the entire fuel system (VST tank, high pressure fuel pump, etc) along with some maintenance the prior owner had failed to do.

I now have a fuel water separator and a lighter wallet, but the motor will only run for ~8 minutes before dying with fuel starvation symptoms (e.g. bulb goes soft but I can sometimes squeeze it aggressively to save the motor from dying). A new low pressure fuel pump didn't help. The mechanic now thinks the high pressure fuel pump is losing voltage and he's waiting on a part.

Two questions:
1. Does this seem like a plausible point of failure for a 6 y/o motor with a couple hundred hours?
2. Am I just incredibly unlucky or is this the usual welcome to boat ownership? I've had the thing for 6 months, enjoyed less than an hour of use out of it, and paid the entire market value of the motor in mechanics fees. Started shopping for new motors...

Leads me to believe you have a fuel supply problem to the motor.

[fairdeal]

Leads me to believe you have a fuel supply problem to the motor.

information lacking;
after the motor runs " for ~8 minutes before dying" -
what has to be done to re-start?

is the primer bulb used to re-fill the VST?
repeated use of the pull-start?

[panasonic]

Is the primer bulb getting somewhat soft or collapsing?

[99yam40]

he said soft, plus if it collapses there would be no way to pump it aggressively as he mentioned.

I still think he should drain the VST when it dies.
this would tell him if the VST ran out of fuel or just that the Pump in there was not running.

does the motor die when just idling for 8 minutes of is it only when under load at higher RPM?

[boscoe99]

information lacking;
after the motor runs " for ~8 minutes before dying" -
what has to be done to re-start?

is the primer bulb used to re-fill the VST?
repeated use of the pull-start?

Nothing new there.

Either not enough germane information or too much useless information.

Talking about posts in general. Not this one specifically.