75 hp Mercury stalls

martinn

Recruit
Joined
Sep 11, 2006
Messages
5
Can anybody give me some ideas concerning the why's in which my mercury 75hp will run good one day then spit and sputter the next? The engine was idling good and then suddenly it slowly sputter's out. I give it full throttle and it acts like it wants to get up and go but can't seem to find the next level. I keep having to choke it to start most of the time. I am new to this. I pump the bulb often because it seems that it loses it's prime. And also it drips fuel at the fuel connector that connects to the motor. I can go full speed at times and then in the middle of saying " Yeeeaaahh " it suddenly just powers down. What is happening? Help me please.
 

lisfisher

Petty Officer 2nd Class
Joined
Apr 27, 2006
Messages
139
Re: 75 hp Mercury stalls

If the primer bulb is loseing pressure you may need a new fuel pump diaphram. You may also have a bad check valve inside the bulb itself.
 

martinn

Recruit
Joined
Sep 11, 2006
Messages
5
Re: 75 hp Mercury stalls

lisfisher said:
If the primer bulb is loseing pressure you may need a new fuel pump diaphram. You may also have a bad check valve inside the bulb itself.

Thanks for your assessment. I'll check into it. Thanks.
 

martinn

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Joined
Sep 11, 2006
Messages
5
Re: 75 hp Mercury stalls

Thanks for your assessment. I will check into it. Thanks
 

martinn

Recruit
Joined
Sep 11, 2006
Messages
5
Re: 75 hp Mercury stalls

When I pump the bulb there is fuel that begins to drip at the connetor at the motor, Is this normal?
 

lisfisher

Petty Officer 2nd Class
Joined
Apr 27, 2006
Messages
139
Re: 75 hp Mercury stalls

no , not normal. If your lucky you may just need a new adapter. Check the adapter and primer bulb first , they are inexpensive parts.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: 75 hp Mercury stalls

You need to install a new connector. The primer bulb does not stay firm once the engine starts. Remember, fuel is being drawn through it, not forced through it. If there is a leak at the connector the fuel pump will draw air through that leak which may very well be the cause of the stalling problem. Also be aware that this can create a lean mixture condition in the engine. Lean mixture means very high combustion temperatures and potential for severe engine damage.
 

martinn

Recruit
Joined
Sep 11, 2006
Messages
5
Re: 75 hp Mercury stalls

I will check these things out and see what happens. I hope something good comes of this. Thanks for your assessments. I will let ya'll know what happens.
 
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