I have a MCM 350 magnum 4bbl, I've rebuilt the carb, new plugs, wires cap, rotor, coil, the boat runs excellent starts good lots of power put the throttle right down and it slams you in the seat til 45mph then it starts missing and sputtering pull back to 3/4 no proplem it keeps pulling soon as you hammer it down again it does it agian.

Jamie.

Have you checked your timing?

Does your tach fluctuate when the miss occurs??

Seems like it is running the bowls dry,check floats,does it do it all the time?
Could be timing too if it does it every time.

be sure to check both base and total timing

also check your firring order to the plugs ( more then likly this is not the problem since it runs fine at lower end but worth checking)


is it a q jet, AFB, or holley carb ??????


let us know how you make out

Probably carb, fuel filters, or fuel pump.

Rebuilt does not always mean 'working properly' unfortunately.

Its a Rochester quadra jet I'm going to double check the float height and timing.