1993 OMC cobra 5.0 (302) running rough issue

[MG2733]

Okay so I need suggestions. 1993 cobra 5.0 (302).

When I start the boat it fires up fine, has somewhat of a spitter/rough idle, once I throttle it up and then put it back to idle it isles fine. When idle is perfect, if I trim up or down, it will begin to sputter, then I rev engine to about 2000 and it idles fine again.

When going from a smooth idle and trying to get to plane, it will get to 2000-2500 rpm and has some sputtering but once it clears out 5-10 seconds it runs fine and will allow me to run 3500-4500 rpm get to top speed etc....

Is this a carb problem? Is it a voltage problem, fuel? I’m stumped.

 

[MG2733]

I also can confirm the plugs, and wires are new. Distributer cap looks fine as well.

 

[Scott Danforth]

if you move the trim and anything coughs....... start by cleaning the battery cable terminals and connections on both ends

the initial idle is probably gunk in the carb needing attention.

 

[MG2733]

Do you think the carb being dirty could also cause the stuttering/coughing between idle to higher RPMs, review fine to about 2000 then hesitates/sputters before making it to higher rpms, if I give it too much throttle it will die during this hesitation, but when slowly increasing throttle it will eventually clear out and go into the higher rpm’s