1997 5.7 mercruiser thunderbolt V

[babyliner24]

Hi all, HELP
\Have a 5.7 thunderbolt V ignition, running rough at low RPM but if I could get over 3000 it was O.K. Changed plugs wires coil and cap Changed fuel filters. running a bit better but still at higher RPM. Running very rich at low RPM also " black smoke from exhaust". Haven't done a compression test as yet, hoping for an easy fix. Slow to get to 3000/3100 on plain but after that seems good

 

[Bondo]

Re: 1997 5.7 mercruiser thunderbolt V

Hi all, HELP
\Have a 5.7 thunderbolt V ignition, running rough at low RPM but if I could get over 3000 it was O.K. Changed plugs wires coil and cap Changed fuel filters. running a bit better but still at higher RPM. Running very rich at low RPM also " black smoke from exhaust". Haven't done a compression test as yet, hoping for an easy fix. Slow to get to 3000/3100 on plain but after that seems good

Ayuh,.... Welcome Aboard,.... It sounds like a Carb problem, but ya don't say what it is,....

 

[achris]

Re: 1997 5.7 mercruiser thunderbolt V

Ayuh,.... Welcome Aboard,.... It sounds like a Carb problem, but ya don't say what it is,....

Ayuh,..... Engine serial number please....

Sounds like the choke stuck on, but without that serial number...?????

 

[babyliner24]

Re: 1997 5.7 mercruiser thunderbolt V

Ayuh,.... Welcome Aboard,.... It sounds like a Carb problem, but ya don't say what it is,....

2 bbl mercarb, choke seems free. motor s/n 0K178906. any hints?