Larger idle jets for Dellorto 38/34 carburetors

Recently I installed larger carburetors to my Madeira 40 outboard to match the ones in 40 XS / 50 HP models. Although the carburetors came from Selva factory the idle jets did not match the to specification. What I got was #65 although Selva documentation says that 40 XS / 50 HP models use #70 idle jets.

My Selva Madeira was not idling very well with #65 idle jets although I have adjusted the idle fuel/air mixture screws.

It's not particularly easy to find Dellorto OVC parts online, I noticed that EUROCARB is one of the few who is selling those. Unfortunately they had only one #70 idle jet available and told that they are not getting more. I ordered the one they had and then the problem was to find another one.

When I got #70 idle jet I noticed that it was exactly the same as #65 idle jet, the only difference was the size of the opening in the tip of the jet. I discovered also that number 70 meant 0.7 mm opening.

I decided to convert the #65 idle jet to #70 by drilling the idle jet using 0.7 mm drill bit.
I was not using a drill, only rotated the drill bit slowly until the opening matched the #70 idle jet.
I was extra careful not to leave any metal parts inside and used compressed air to clean the idle jet.

Once I installed these #70 jets to my Selva Madeira 40 it started to run more smoothly, at least I felt so.

From top to bottom:
#65 idle jet
#70 idle jet
#65 idle jet converted to #70 using 0.7 mm drill bit