AQ260 Chevy 350 cutting out at 3000 rpm's

[zentodd]

Hi guys and girls,
i need help brainstorming what to do next.
I have a 1987 Bayliner with an AQ260 Chevy 350.
Serial # cu46817
I just removed the engine to fix the out drive and seal on the bell housing.
When the engine was out I replaced the fuel separator, plugs, wires, rotor / cap (electronic ignition) and various other tune up stuff.
I took it out on the water and it ran great for an hour. Then on the way back to the ramp it started cutting out at 3000 rpm's.
It idles fine and goes great until you push the engine past 3000 and then it goes flat.
What do you guys think I should do?
The things that come to my mind are
- fuel starvation (fuel pump or float bowl)
-dead cylinder
-electronic distributor
-bad fuel
Thanks in advance for any help!

 

[Bondo]

- fuel starvation (fuel pump or float bowl)
-bad fuel

Ayuh,..... Check the Contents of the fuel filter,.....

Connect a remote tank fulla fresh gas to the fuel pump, 'n try it,...

 

[zentodd]

Thank you - it needs a load on it to do it. It runs great on the driveway
I suppose If I can run it on an alternative fuel tank on land I can do it on the water. I'll try it.

 

[jerryjerry05]

It sounds like a fuel restriction some where???
The vent line or a pinched line, filter in the carb??

The coil can get hot and cut out too.
Start it up and go for a ride.
When it breaks down go back and touch the coil.
You should be able to keep your fingers on the coil under normal operation.
Too hot= bad.

 

[jeffnick]

You can tell zero by running it in the driveway.
In addition to fuel restriction I'd check...
Water in the float bowl?
Point gap, bad condenser, timing or defective advance, bad plug(s), spark leak (bad cap, wires or connections).
Choke not coming off all the way
Air intake restriction
Jet's plugged
Throttle linkage

What do the spark plugs look like?