Originally Posted by StihlMechanic
Fingernail polish for external plugs only. Nothing seals permanently to the internal welch plugs so IF and when I need to replace a plug I dont, I just replace the carb. Years ago, before ethanol, fingernail polish worked. With ethanol, nothing seals permanently and with carbs priced at 30 bucks msrp, it only makes sense just to replace it. The only repair I will do to an old carb is replace a stiff metering diaphragm or leaking inlet needle. Cant put alot of time in an old carb when labor rates are 75+ an hour.
Installing new welch plugs and sealing with super glue works just fine--never had any call backs. It doesn't take much--apply with a toothpick at the juncture of the plug and carb body only, then wipe off excess. I prefer the gel over the thin variety as you minimize the risk of it seeping past the welch plug into the ports below. I never did feel that finger nail polish was a good choice since it is lacquer based, therefore subject to carbon based compounds.