1995 SENTRY 19, Optimax 150: Fuel Problem
Posted: Sat Jul 08, 2017 6:26 pm
I have mostly finished the restoration on the 1995 Boston Whaler SENTRY 19. We took it out on July 3 and July 4, 2017. The [Mercury 150-HP OptiMax] engine would surge under 3000-RPM, and we only once got the boat on plane. After doing much googling, I narrowed down [the cause of the engine surging under 3,000-RPM] ] to either the tracking valve, fuel pump or pumps, or injectors.
S/N on this Optimax 150 is 1B444899, and is a 2006 year.
Pulling [spark] plugs, their apperance all looked similar with each other and had the characteristic brown deposits. The [peak cylinder pressure] is within the 10-percent variation on all cylinders. The air [injection] pressure is 80-PSI when high pressure fuel is at 90-PSI. Voltage is about 12.5-Volts at idle, 13.5-Volts at 1,000-RPM and 13.8-Volts at 2,000-RPM.
I have narrowed down [the cause of the surging] to the medium pressure pump--I'm pretty sure--because the brass outlet fitting on the top is hot to the touch after running a few minutes. Also when using the battery and connecting wires directly to the pump yields no rotation or flow, and the current draw is 3.51A. The resistance between the conductors marked (+) and (-) is 5.3-Ohms.
The fact that there is no rotation of the pump while there is current draw tells me the pump is probably bad. I just want to run this past reader before digging into the pump to see if it's obstructed or if the motor is bad.
Here is a pic of how the SENTRY 19 came out. Still a few trailer things to do but that's winter stuff.
S/N on this Optimax 150 is 1B444899, and is a 2006 year.
Pulling [spark] plugs, their apperance all looked similar with each other and had the characteristic brown deposits. The [peak cylinder pressure] is within the 10-percent variation on all cylinders. The air [injection] pressure is 80-PSI when high pressure fuel is at 90-PSI. Voltage is about 12.5-Volts at idle, 13.5-Volts at 1,000-RPM and 13.8-Volts at 2,000-RPM.
I have narrowed down [the cause of the surging] to the medium pressure pump--I'm pretty sure--because the brass outlet fitting on the top is hot to the touch after running a few minutes. Also when using the battery and connecting wires directly to the pump yields no rotation or flow, and the current draw is 3.51A. The resistance between the conductors marked (+) and (-) is 5.3-Ohms.
The fact that there is no rotation of the pump while there is current draw tells me the pump is probably bad. I just want to run this past reader before digging into the pump to see if it's obstructed or if the motor is bad.
Here is a pic of how the SENTRY 19 came out. Still a few trailer things to do but that's winter stuff.
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