Mercruiser 3.0 Loosing fuel at full throttle

jay127

Seaman Apprentice
Joined
May 17, 2010
Messages
47
I have been resurrecting a 1987 Well craft with a 3.0 mer-cruiser (1988). I've ran into a few bumps but have finally got it in the water. The biggest issues Ive had are fuel issues. When we first test drove it the boat would get real sluggish when cornering (almost stalling). We then decided to add a fuel water separator after reading posts on here. We also installed a external 12 gallon tank with a gas line and primer ball. The boat now runs perfect except after running for 45 minutes or so it gets sluggish at full throttle. I notice also that the primer ball is empty when this happens. I am thinking of adding a electric in-line fuel pump just to check if thats the issue. Is there anything else I should try before going this route. I appreciate any suggestions.
 

cr2k

Captain
Joined
Mar 19, 2009
Messages
3,730
Re: Mercruiser 3.0 Loosing fuel at full throttle

Is the vent open on the tank? If it is it may not be big enough for the 3.0 or there may be a restriction at the pick-up. You should be running 5/16 or 3/8 fuel line 1/4" is not enough.
 

jay127

Seaman Apprentice
Joined
May 17, 2010
Messages
47
Re: Mercruiser 3.0 Loosing fuel at full throttle

I will try putting larger line size. Would that make sense that it runs that long and then starts acting up.
 
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