Carb leak at throttle arm

[Cardiff Kook]

Leaks at throttle arm when opened/closed.

Mechanic said get a new carb.

That my best bet? Or do i try to fix it? Who do I buy one from?

Currently Marv-Shebler MA3SPA

 

[BC12D-4-85]

CK, are you referring to fuel seepage out around the throttle arm (or potentially air leaking in)? That fuel seep can happen when the accelerator pump is activated when the engine is off, or sometimes at shutdown, from condensed fuel above. Fuel drains down and seeps out around the throttle shaft. There's two replaceable bushings around the throttle shaft that can wear. When they do the throttle shaft gets loose and the fuel can leak out more, or air leak in. Fix is overhaul or replacement. If your A&P says do it best get it done. Others know more where to source repair or replace.

One source: https://www.aircraftspruce.com/menus/ep/carburetors_00marvelsch_carbs.html

Engine eligibility: https://msacarbs.com/technical-data/engine-eligibility/

Gary

 

[Cardiff Kook]

Fuel comes out when moved back and forth.

I will just buy a new one.

Expensive week for me

 

[brown bear]

If I had a ma3spa that I was happy with how it was running, I would check the float and then repair as needed .
but that’s just me.

 

[BC12D-4-85]

I had my last MA3SPA done by Alaska Aircraft Engines in Anchorage. Less than $1K incl. shipping from Fairbanks. Not sure of the right term - overhaul or rebuilt - but was pleased. New parts/works good. Old accelerator pump didn't work right plus some debris got through the inlet screen. We drained what we could, but IA said fix.

One thing for sure is they don't unwear or fix themselves if there's some problem an A&P sees. The other thought is older uncommon models may be hard to find. Unless there's a core exchange or available for restoration there's fewer around if needed.

Gary

 

[fishhook]

Common issue. Seems a lot of guys do not measure out the wear on the shaft and body/bushing if so equipped. Seen some with over .100 of slop. When doing a bubble test its unreal the air leakage on the intake from there. Just stick a new carb on.

 

[RedOwlAirfield]

Leaks at throttle arm when opened/closed.

Mechanic said get a new carb.

That my best bet? Or do i try to fix it? Who do I buy one from?

Currently Marv-Shebler MA3SPA

I side with your mechanic. Less risk of failure - although failure is always a possibility. There are lots of reman places that do a bang up job. I used to work for the Rayloc division of NAPA. I've seen them package new units as reman because they had to fill an order. So reman can be good. But honest to gosh new is much less likely to fail.

It's just my personal style of course, but any time I can't just pull over to the side of the road I like to try to minimize every possibility of negative occurrence. Stuff will still happen, but less often.

Of course many many folks haven't bought anything new in decades and they're getting along fine.

 

[hotrod180]

Does anyone do carb overhauls? I would think there's at least one carb specialty shop out there.
Or is the only option an exchange for an overhauled or new unit?

 

[BC12D-4-85]

^^^^See Post #5

Gary

 

[hotrod180]

Thanks Gary.
I generally prefer to overhaul what I've got, rather than exchange for a new or OH'd unit.
Sometimes doing the exch thing, you get a unit that comes with it's own set of issues.
"Better the devil you know...."

 

[BC12D-4-85]

Spruce's carb page explains overhauled versus rebuilt specs under the Q&A at the bottom:

https://www.aircraftspruce.com/catalog/eppages/tempestvolarerebuildoverhaul.php

I never knew there was a difference. Is it worth paying more?

Gary