1962 evinrude needle valve assembly on carb

[BsBrett]

I have a 1962 evinrude lark IV, 40 hp, model 35530 it runs great when the needle is adjusted in the correct spot using the rich/lean handle but I can’t get that handle to stay in place, it freely turns then runs horrible again.

Anyone have a idea what might be wrong or needs to be replaced?

Any help is greatly appreciated!

 

[Chris1956]

I do not remember what my big twin had, but most needles have springs on them to keep 'em tight. You could also use teflon tape on the threads to add friction. Be careful not to let it get into the carb.

 

[racerone]

Use a 7/16" wrench and tighten the packing nut on the low speed needle !!----Add more packing if needed.