Venturi Size for Cox Tee Dee

I have many Tee Dee motors. .010 .020 .049 .051 also medallion

I have one .020 that is running good but struggles sometimes to prime before running. One venturi jet was a bit elongated so I drilled it back to original size. .65 mm. Can the venturi jets be made larger or bad idea?

I was wondering the venturi inlets are .65 mm for the .020 and the fuel supply line side of the needle is about .75 mm if I remember correctly. Would there be any benefit or harm in enlarging these hole sizes? I have ensured they are round by drilling them to the original size of .65 mm. One was somehow a bit elongated but all are good and round now.

Thanks

You can enlarge the venturi, but... it has an adverse effect on fuel draw and TD’s need all the help they can get. If you run a pressure bladder you can get away with an enlarged venturi and it gives you a little more oomph. No need drill out the sprinkler jets or the feed hole, they can deliver more fuel than your engine will ever need, plus you will just be compensating for the increased flow with the needle valve which kind of negates your efforts.

Ron