Mercruiser 3.0LX Bogging down at 2K rpm ?

[Rake722]

Hi All,
I have a 1994 3.0LX fitted with a 2bbl mercarb.
When pushing to 2000 rpm the engine bogs down and stalls.
She idles just fine, everything as normal until I hover over 2000 rpm and she bogs and stalls.
Now if I push past 2k rpm to 3k rpm she pushes through without stalling.
She has had new dizzy cap, new ingition module and timed up according to spec from base timing made.
I am remote from the boat and cannot simply go out and check stuff so I would appreciate any reasons the engine would do such a thing.
Carb has been rebuilt but the accelerator pump plunger was too small so I reused tohe

 

[Doug L.]

I had a very similar issue with my Mercruiser 140 last summer. Idled perfectly and accelerated fine but when I got to 1800 - 2200 RPMs, it would stall and lose power horribly but if I pushed past up to 3000 it smoothed out or it seemed. Turned out my mechanical advance mechanism in my distributor (points style Delco) had worn spots on the stop studs allowing it to over advance about 11-15 degrees (used the arc length formula to determine maximum advance (IIRC is 28 degrees at 2k rpms) point, approximately 1.96" to right of factory mark. Marked my harmonic balancer and saw I was wayy off. Purchased an NOS dizzy on eBay and solved my problem. Not sure if this is your issue if you have electronic But would def recommend verifying your maximum advance.

Cheers,
Douglas

 

[Rake722]

I had a very similar issue with my Mercruiser 140 last summer. Idled perfectly and accelerated fine but when I got to 1800 - 2200 RPMs, it would stall and lose power horribly but if I pushed past up to 3000 it smoothed out or it seemed. Turned out my mechanical advance mechanism in my distributor (points style Delco) had worn spots on the stop studs allowing it to over advance about 11-15 degrees (used the arc length formula to determine maximum advance (IIRC is 28 degrees at 2k rpms) point, approximately 1.96" to right of factory mark. Marked my harmonic balancer and saw I was wayy off. Purchased an NOS dizzy on eBay and solved my problem. Not sure if this is your issue if you have electronic But would def recommend verifying your maximum advance.

Cheers,
Douglas

Thank you dougles but mine has the ignition module as opposed to points.