1988 mercury 100hp no acceleration

[greg68]

The boat will start but idle rough and will run fine about 3 miles per hour. But when I throttle, after setting up over night, it will accelerate fine for about 15 seconds and then slow to an idle at full throttle. When I try to accelerate at full throttle when it hasnt set up overnight, it will not even go faster than mph. It is 100hp oil injected and serial # 0B312314. Please help.

 

[CharlieB]

Re: 1988 mercury 100hp no acceleration

You may have a serious fueling issue.

Start at the carbs, pull the fuel line off, stick into a suitable container, squeeze the primer bulb and observe the fuel stream, strong flow with each squeeze, Right?

Pull the Lanyard cord so that the motor won't start, then crank the motor and observe the fuel stream again. almost as strong and solid as the primer bulb?

No? Clean every fitting, replace any/all old/cracked hoses, and rebuild the fuel pump.

Retest.