Hello
1988 Mercury 2 Stroke Oil Injected 3 Cylinder Outboard
SN - B302789
I dont know much about these so ill try to make as much sense as i can in regard to the issue im having.
I seem to be having a flooding issue, and i think its coming from the pulse hose that runs from the face of the fuel pump directly to the crankcase. Is it possible for fuel to reach the crankcase from that line? If i pull the line from the crankcase and pump the primer bulb it spews gas out of the pulse hose and very little seems to get to the fuel filter, then up to the carbs. The primer bulb does not seem to stiffen up very much either if i keep pumping it. If i pinch that line (pulse hose) and run the motor it runs great, and the primer bulb will also get hard in this scenario. The second I let off, the motor stalls out.
I rebuilt the carbs. Tore them down, ran them through an ultrasonic cleaner, checked the float needle and bowl and those are good (air tested them to make sure the float needle was sealing)
I attached a screenshot of the fuel pump diagram and pointed out where the fuel is spewing from if i disconnect it from the crank case and pump the bulb. I cant seem to find any info saying if this is normal or not. From my understanding this is only supposed to be a vacum line that pulses a diaphragm in the pump. I should also mention that gas comes out of that line when i try turning the motor over.
In addition to the flooding, its also just dumping gas like crazy. Last time I ran the boat it dumped 6 gallons in less than an hour run time. I ended up needing a tow off the lake. Gas seemed to have just flooded into the crank case and dumped out of the exhaust. Could barely keep in running that day.
Hope someone is able to clear this up or at least point me in the right direction. My guess is its a bad fuel pump? Thanks for your time!
1988 Mercury 2 Stroke Oil Injected 3 Cylinder Outboard
SN - B302789
I dont know much about these so ill try to make as much sense as i can in regard to the issue im having.
I seem to be having a flooding issue, and i think its coming from the pulse hose that runs from the face of the fuel pump directly to the crankcase. Is it possible for fuel to reach the crankcase from that line? If i pull the line from the crankcase and pump the primer bulb it spews gas out of the pulse hose and very little seems to get to the fuel filter, then up to the carbs. The primer bulb does not seem to stiffen up very much either if i keep pumping it. If i pinch that line (pulse hose) and run the motor it runs great, and the primer bulb will also get hard in this scenario. The second I let off, the motor stalls out.
I rebuilt the carbs. Tore them down, ran them through an ultrasonic cleaner, checked the float needle and bowl and those are good (air tested them to make sure the float needle was sealing)
I attached a screenshot of the fuel pump diagram and pointed out where the fuel is spewing from if i disconnect it from the crank case and pump the bulb. I cant seem to find any info saying if this is normal or not. From my understanding this is only supposed to be a vacum line that pulses a diaphragm in the pump. I should also mention that gas comes out of that line when i try turning the motor over.
In addition to the flooding, its also just dumping gas like crazy. Last time I ran the boat it dumped 6 gallons in less than an hour run time. I ended up needing a tow off the lake. Gas seemed to have just flooded into the crank case and dumped out of the exhaust. Could barely keep in running that day.
Hope someone is able to clear this up or at least point me in the right direction. My guess is its a bad fuel pump? Thanks for your time!