90 Mercury fuel problem

[ncroger]

When I started out the other day I primed the fuel bulb but it got only semi hard. Engine fired up and idled great. Went out on lake and ran at medium speed. Stopped to pull kids on water tube after about 3 minutes engine slowed down and ran out of fuel. Vent cap was open. Tried to prime bulb but it stayed soft and I could not prime fuel.

The next day I was able to prime bulb to a reasonable hardness. Engine fired up and went out on lake but the same thing happened after 3 minutes. I could not prime fuel again.

Mechanic has checked the fuel pickup and it looked good and he cleaned it anyway. Put a new fuel line and bulb and it primed up good. Started up fine but after 3 minutes on the lake it just quit again. Same thing, fuel bulb was soft (not collapsed) and could not prime fuel. We are stumpped.

Anyone have any suggestions?
Thanks

 

[zapped77]

Re: 90 Mercury fuel problem

I just had a problem with my merc 45hp outboard and it sound the just like the problem you are having I changed fuel lines, rebuilt carb and checked tanks and the motor would not run correctly and today it came to me check the float in the carbs.

That was the problem the floats were not letting enough fuel in to the carbs so the motor would run for a few minutes the start cutting out due to lack of fuel the fuel line bulb would be soft.

If you pump the bulb slightly will it keep running? I would check the floats levels if you have a repair manual it should show instructions.

good luck