VIDEO: Runs Perfect For A Minute Then Red Light Comes On, Motor Shutters & Stops.

[bobgritz]

2007 20HP Yamaha 4 Stroke starts up great. Red light comes on after about a minute then the motor shutters and when you give it throttle it starves, backfires and stops. Rebuilt Carb. 135 Lbs Compression.

View attachment Yamaha 20HP Red Light.mp4

 

[boscoe99]

Why is the motor allowed to keep running when the warning light is on?

 

[bobgritz]

Why is the motor allowed to keep running when the warning light is on?

2007 20HP Yamaha 4 Stroke starts up great. Red light comes on after about a minute then the motor shutters and when you give it throttle it starves, backfires and stops. Rebuilt Carb. 135 Lbs Compression.

View attachment 343858

Why is the motor allowed to keep running when the warning light is on?

'Allowed to run' because the first thing we did was to pull oil pressure sensor and continuous pressure is around 40-45 lbs. Problem doesn't seem to be the pump and there's no fear of damage. If re-started immediately after shutdown, motor again runs normal but after 30 secs it goes into shutter-mode. Seems to be running only on one cylinder. Hoped someone encountered similar issue.

 

[99yam40]

well if the alarm is not for low oil pressure then it is probably for overheat or maybe oil pressure out of range

 

[mike_i]

Have you checked the fuel filters? Try squeezing the primer bulb when it starts to die.

 

[bobgritz]

Have you checked the fuel filters? Try squeezing the primer bulb when it starts to die.

Cleaned out fuel filter and did squeeze the bulb (it stayed hard). Rebuilt the carb. It's almost as if the motor goes into some sort of safety mode when that red light illuminates. Before that, it's running like a Swiss watch.

 

[mike_i]

what's the fuel level in the filter while running and as it peters out? Crack the fuel tank cap open and try it.

 

[99yam40]

Cleaned out fuel filter and did squeeze the bulb (it stayed hard). Rebuilt the carb. It's almost as if the motor goes into some sort of safety mode when that red light illuminates. Before that, it's running like a Swiss watch.

yep the red light tells you the motor has a problem and RPM is limited also to help you know to look at the light and shut down the motor as soon as it is safely possible