91 comp Cutting out at top speed

[jbjr]

OK this is my first post, I will try to make it short as possible yet provide all the details and info
This past spring my boat had been in the garage for 16 month due to job relocation and a new son.
Decided in early spring to change out everything I could that was old and or neglected while I had time.
New
Plugs, plug wires, distributor cap, rotor, rebuilt carb, impeller, thermostat
Changed oil, fuel filter, gaped plugs and set timing
After getting the Carb dialed in the boat has run as well as it did when I bought it new until yesterday.
As we headed in just before dark the lake was like glass so I opened it up. After about 30 seconds at top speed I notice a slight reduction in RPM about 2000 and then intermitted missing not really a back fire just a chug and miss with reduced power and speed. Backed it down, ideal was smooth neutral rev-up was smooth and sounded great. Punched out of the hole again same thing. I was getting dark and I had my 3.5 year old with me so I did not do any really trouble shooting on the water. I was think fuel pump, anyone else have ideas? I believe the fuel is good, filled up the truck at the same time. I also have a fuel filter and water seperator also new this year.

[92SupraComp]

try a different coil. Not just a new one. A known working one.

[awesomesteven]

Sounds to me that you might have a carb issue. I'm no expert at carbs (and actually had someone rebuild mine b/c i couldn't tune it right), but since its bogging down at top speed it might be a leak somewhere (check valves, leaky o-ring at the fuel line connector...). The more throttle you give it, the more pressure the vacuum creates. So I'm guessing that the chugging or misses your getting are from the leak opening and closing back up. I'm sure someone will chime in here, but in the meantime Holley has a good forum and I'm pretty sure they have a few posts regarding the same issue.

[Cusefan78]

Yeah that would be my guess. Seems like it may not be getting enough fuel or air.