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My darn carburetor started leaking

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Alex Clark

Registered User
Life Long Alaskan
It was parked for a few months after the annual. Something may have contaminated the system due to a tank change.
Not sure about the fuel that was sitting in the carb bowl. Leaks out the carb breather box.

These days ... Is it cheaper to have a carb re-built or just buy a rebuilt one via core exchange?


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Is it cheaper to have a carb re-built or just buy a rebuilt one via core exchange?
Either one sounds expensive. I would want to look inside to find the issue before spending money. An A&P can open it up, replace parts and reassemble. Why buy the whole carb if it just needs a float or needle valve and a parting gasket?
So is the float sticking or is the carb bowl gasket leaking. You will see stains down the side of the carb bowl if it is the gasket. The gasket is a dirt simple fix.
It will look like a carb float leaking if primer us not locked. One thing to check also check for debris in float needle.
Auto gas gives us problems with Neoprene needles in the small Strombergs. Not an MS expert, but I would guess that Avgas will solve your problem unless the needle has swollen and deformed.

Yes, selection of mechanics is critical. Unfortunately mechanics wages are a lot higher at auto repair facilities, (not to mention reduced liability) so I wish the newbies with airplanes good luck.

In 1967 I discovered my carb drain plug held in place with window putty. Nobody other than me has touched my Cub since, except for an occasional valve seat. I do my own carbs.
As previously mentioned, check for a leaking primer first. If it is the carb leaking, you can order a float kit from Aircraft Spruce. Kit comes with gasket for the carb and new locking clips. If the inlet filter was removed for cleaning during the annual, it could be that you need a new gasket on the inlet filter. That's a $5 item at AircraftSpruce. Mogas shouldn't affect the needle and seat in a MS carb like some of the Strombergs that have a neoprene needle tip.

-Cub Builder
If it were mine I'd make sure there's no debris in the entire fuel system. What that involves reputable A&P's know how to flush and inspect.

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