1990Bayliner CIERA 2556 Difficult to restart the engine

[HotRoad]

Please help us.
We’re working on repairing the following ship’s engine, but it doesn’t work.

•The engine is 7.4L BRAVO GM 454 V-8
•The ignition system is Thunder bolt5
•The engine serial number is OC869161

<The condition>
When the engine is cold or immediately after warm-up, it does work.
When over 30minutes have passed after the engine stopped, it doesn’t work even with the accelerator pomp.

The engine gradually starts up, when we start the starter motor and open the throttle slowly. It also does work, immediately after this, but after over 30minutes, it doesn’t.

<already replaced parts>
Fuel pump
Fuel filter
Ignition coil
Spark plugs
Picup sensor
Distributor cap
Rotor
Exhaust
carburetor
Thermostat
Rush adjuster
Intake manifold gasket
Starter motor

 

[Grub54891]

Rebuild the carb. Sounds like it may leaking, flooding, or starving due to plugged low end passages. When cold the choke is drawing more fuel so it will start.

 

[HotRoad]

Rebuild the carb. Sounds like it may leaking, flooding, or starving due to plugged low end passages. When cold the choke is drawing more fuel so it will start.

Rebuild the carb. Sounds like it may leaking, flooding, or starving due to plugged low end passages. When cold the choke is drawing more fuel so it will start.

I replaced it with a new carburetor It was no good

 

[Bondo]

Ayuh,..... Welcome Aboard,....
When you tryin' start it,... Do you advance the throttle,..??

 

[HotRoad]

Regarding cold start, it is possible to start by operating the acceleration pump and returning the throttle.

After warming up, stop the engine and wait for at least 30 minutes then gradually open the throttle more than half and turn the starter motor for long before starting. (The engine may not be enabled).
but immediately after the engine is stopped- it can be enabled without operating the acceleration pump.

 

[nola mike]

Regarding cold start, it is possible to start by operating the acceleration pump and returning the throttle.

After warming up, stop the engine and wait for at least 30 minutes then gradually open the throttle more than half and turn the starter motor for long before starting. (The engine may not be enabled).
but immediately after the engine is stopped- it can be enabled without operating the acceleration pump.

Huh?