Leaking Carburetor

mvivion

SPONSOR

Bozeman,MT

• Feb 5, 2021

• #1

My O-360 A1A is all of a sudden leaking just a bit of gas onto the drip Pan after each flight. Doesn’t seem to continue very long, but leaves a bit of a blue stain in the pan. After a day or two, it’s stopped.

Not a lot of fuel each time, but concerning.

Ideas where to start? This is an Avcon conversion, and without unassigned a LOT of stuff, you can’t see any part of the carb.

MTV

 

Gordon Misch

MEMBER

Toledo, Wa (KTDO)

• Feb 5, 2021

• #2

Just finished (I hope!) Going through that. My MA4SPA carb started dripping last summer, stopped for a while, then got worse. I have overhaul paperwork from Avstar, 2011. About 700 hours sunce then.

Took it apart and discovered significant wear on the float frame where the needle contacts, significantly worn float shaft, and the float setting very high - almost zero.

I installed new float, shaft, and valve assembly. Just finished installing today and so far seems good.

 

D

DENNY

SPONSOR

• Feb 6, 2021

• #3

If you are shutting the fuel valve off look at the fuel flow cube. The fittings like to leak if they have been reused. DENNY

 

mvivion

SPONSOR

Bozeman,MT

• Feb 6, 2021

• #4

DENNY said:

If you are shutting the fuel valve off look at the fuel flow cube. The fittings like to leak if they have been reused. DENNY

Click to expand...

Only time my fuel valve is shut off is for maintenance.

MTV

 

Steve Pierce

BENEFACTOR

Graham, TX

• Feb 6, 2021

• #5

Coming out of the carb throat, accelerator pump plunger, carb split line?

 

mvivion

SPONSOR

Bozeman,MT

• Feb 6, 2021

• #6

Steve Pierce said:

Coming out of the carb throat, accelerator pump plunger, carb split line?

Click to expand...

I was afraid someone was going to ask that....looks like the cowlings coming off. PITA to re-install by one person, but looks like it's gonna get cold here soon.

Problem is, leak only happens for a little while after shutdown. May have left fuel stains, though.

Stand by.

MTV

 

TVATIVAK71

SPONSOR

ANC

• Feb 6, 2021

• #7

Had a similar issue recently. Old primer was leaking and fuel was making its way from cylinder fitting down manifold and into airbox. Blue stains for a short period after it was flown.

 

Steve Pierce

BENEFACTOR

Graham, TX

• Feb 6, 2021

• #8

I'd let it warm up and see if it still drips. These things seem to start when it gets cold and a lot of times disappear when it warms up.

 

hotrod180

FRIEND

Port Townsend, WA

• Feb 7, 2021

• #9

mvivion said:

Only time my fuel valve is shut off is for maintenance. MTV

Click to expand...

Why's that?

 

mvivion

SPONSOR

Bozeman,MT

• Feb 7, 2021

• #10

hotrod180 said:

Why's that?

Click to expand...

Mostly because I’m human, therefore I make mistakes.

Too easy to miss on a start up......yes, I know, refer to above^^

And, why turn it off? I’ve never heard a valid reason to do so, except during maintenance. If you’re really worried it’ll leak, get it rebuilt.....

MTV