Mercury 40HP lack of acceleration

[peter0614]

Good Morning <br />My 1990 40hp Mercury stars fine and works fine at low speed, but does not GO when more acceleration is requested. Sometimes it does accelerate but it takes few minutes to get to full throttle.<br />Thanks

 

[achris]

Re: Mercury 40HP lack of acceleration

You'll have 2 carbs on that engine. I'd open the idle mixture screws about 1/4 turn each (richer). Just to see if that fixed the problem. If it doesn't then check the fuel pump and make sure you don't have any air leaks in the system.