Logo
FULL SITE MENU

Yamaha VF90 shuts down when running - like key turned off - no ecm codes recorded

G

GGraham

New member
Our VF90 outboard shuts down after running for approx 30 minutes. shuts down like the key was turned off. No ecm codes shown when the dealer scanned the unit. They replaced the voltage regualtor but the engine still dies at various speeds. Cable connections are tight etc. Any ideas would be greatly appreciated

G. Graham
 
Re starts after pumping primer bulb. 12 volt marine battery 3 years old and all conections have been cleaned and tightened. Replaced all fuses 50 amp, 30 and 2 @ 20 amp. Checked fuel connections at the tank location on the pontoon boat. Problem is still present. Runs fine for awhile and just stops -just like the key was turned off. It will run fine afterwards and other times it will stop 3-4 times before geting back to the dock. Wondering if this could be a faulty main power relay or faulty electric fuel pump.
 
GGraham said:
Re starts after pumping primer bulb. 12 volt marine battery 3 years old and all conections have been cleaned and tightened. Replaced all fuses 50 amp, 30 and 2 @ 20 amp. Checked fuel connections at the tank location on the pontoon boat. Problem is still present. Runs fine for awhile and just stops -just like the key was turned off. It will run fine afterwards and other times it will stop 3-4 times before geting back to the dock. Wondering if this could be a faulty main power relay or faulty electric fuel pump.
Click to expand...
And if the primer bulb is not used then it does not start?

Before the voltage regulator was replaced was your volt meter indicating high voltage? How high?
 
The pontoon does not have a voltage regultor guage. Problem existed before the voltage regulator was replaced by the dealer. They figured,due to no ecm codes being recorded/stored that that was the issue. Now, as of 1 hour ago, priming the bulb, the motor will not start. Bulb is soft and mushy does not get hard even after pumping 10-15 times. Had to paddle the pontoon in today - not fun especially at 77 years of age. Motor is a VF90LA 2022 and has been serviced/stored at the dealer. Going to get a new priming bulb this week and hopefully that solves the problem but I suspect it is more likely somehting to do with a fuel pump. best guess!
 
If the bulb is flattening when the motor has died, or the bulb is not readily expanding after it has been pressed, that indicates to me the problem might be the fuel supply system. Bulb is not getting the fuel it needs when released or when the fuel pump is operating.
 
Thanks, I am goig to get a new priming bulb as ours has not be replaced since the boat/motor was purchased in 2022. If that does not work, I will have to figure out if it the fule pump. I terrible boating season so far.
 
I am guessing a fuel system problem upstream from the bulb. Something restricting fuel flow to the bulb. Think of a partial clog. Bad pickup tube. Bad antisiphon valve if you have one.
 
Back
Top