the top holes are just for  the idle circuit of the  carb .    hopefully you have replaced a plug over those small  holes …  (sorry had to ask)

if the carb drips  the float  is not adjusted properly. is the float level with the carb body  when flipped upside down ?  float not upside down is it ??

carb float is just like a toilet bowl tank float.   full=> stops the inflow

did you do a proper  blow test on the carb before installing it  to confirm the inlet  needle shuts the inflow of air 100%

did you download  yourself a copy of the bible  Johnson  service manual  from Garry’s drop box ??

I had same issue on a RD14,replaced crankshaft seals and problem was fixed.

• This reply was modified 3 years, 11 months ago by stanley.

Stanley,   I usually also replace the crankshaft seals on RDs but to date have not stopped the leak.   My boat is in the water all summer which gives even a small leak a lot of time to show.  I think the leakage is from the carb throat.  Can’t see that changing c’shaft seals would affect the carb – but maybe so.    Anyway disconnecting the fuel line does help a lot.

I’m wondering if the carb with the full butterfly was used in competition. When I raced, all of the Stock outboard engines were required to be equipped with a full butterfly valve. The holes that exist below the area that must be covered by a Welch plug are low speed, idle fuel orifices. If the butterfly completely closes the carb rear throat, no air will flow, and no fuel will be drawn into the engine thru the idle ports. Just a thought. Try the butterfly from the other carb. Just a thought. R.T.