90 hp Mercury question

[big_oshea]

I have an 1987 Mercury 90 hp outboard. On the way back in this weekend my motor died on the water at "no wake" speed. It restarted and we made it home, but I had to push down on the throttle. We I got home and began flushing the engine, it ran for a little and died, then would not restart. I tried to push on the primer bulb and it would not "get hard." I have replaced the bulb and it still will not "get hard." What is my next step in troubleshooting this problem?

 

[partyboat21]

Re: 90 hp Mercury question

make sure your line from the tank to the motor has no cracks anywhere. when you prime the bulb listen to see if you hear it sucking air,if you do theres a break in the line somewhere and you're not getting fuel or feed to carb

 

[big_oshea]

Re: 90 hp Mercury question

I don't hear sucking, but I do hear a blowing sound and when the engine cover is off, I can feel air blowing. Someone told me it might be the diaphram..."I would say you need to see if a carb is overflowing, if not then look at the fuel pump, the fuel pump has check valves and diaphrams in it. It is driven by crankcase pulses created when the piston on two cylinders move up and down. If the diaphram splits or has a hole in it, raw fuel will be pumped into the crankcase and flood at least one cylinder, and will not supply the proper amount of fuel to the carbs. The pump is square and has four bolts, two of the bolts go thru the pump and gasket and thread into the engine block, remove those two screws/bolts and pull it away from the block. Gently squeese the bulb and watch for any fuel to come out the hole in the back of the pump. If it does then the diaphram is bad. You can buy a diaphram kit and repair, or just buy a new pump, the kit will be the cheapest and comes with instructions. Use caution when working with or around gasoline, protect your eyes, skin and watch out for ignition sources. Clean up spills."