Mercruiser 3.0 Bog/hesitation/Stall issue

[Gmorcos37]

Hello all,


​​​​​First post here.
Ill make things short but basically my carbureted Mercruiser 3.0 sterndrive is having bogging and occasional stalling issues when giving quick acceleration. Under slow acceleration there is occasional hesitation but runs smooth once at speed.
Any ideas would be helpful.

Serial #: OM377830

Things replaced so far:
Carburetor rebuild
Flame arrestor cleaned
Spark plugs
Plug wires
Distributor cap
Rotor
Fuel pump
Anti siphon valve

​​​​​​VIDEO for reference:

https://youtu.be/QYld6pjgXME


​​​​​

 

[Bondo]

Carburetor rebuild

Ayuh,...... Welcome Aboard,...... It sounds like the accelerator pump isn't providin' enough gas,......

 

[Gmorcos37]

Ayuh,...... Welcome Aboard,...... It sounds like the accelerator pump isn't providin' enough gas,......

That's what I thought as well but it was replaced and moving the notch to add more fuel on the accelerator pump arm makes no difference

 

[T4Frog]

Is it possible during the carb rebuild, when installing the new float level, it was miss-measured, and is not allowing filling fast enough?

 

[Scott06]

I would start with verify the spark with a spark gap tester, nice blue spark that jumps a 7/16" gap or so. I don't think spark is the issue, just verify. Likely re- rebuilding the carb will fix it. Possible float level is off, passage is plugged or accelerator circuit isn't working fully

 

[MBAKER]

Who rebuilt the carb? Assuming this is a Rochester or mercury copy?

I'd double check the accelerator pump spring. I had this happen once and the spring that came in the kit was softer than the original, replaced with old stiff spring and it fixed the problem. The stiffer spring will give stronger shot of fuel on initial throttle whereas the softer one delays it a little bit.

 

[Scott Danforth]

when you cleaned the accelerator circuit, did you chase out every passage?

is the discharge check valve functioning? outlet nozzles squirting?