Carburetor Main passage bleeder

[hanleyclifford]

Art - I would not be comfortable using hose (not even approved marine) at this location. A copper flare type led off to a valve might be ok. Regards, Hanley

[ArtJ]

Thanks for the info Hanley

Are you at a point of suggesting what would be the "best shot" for a dry trial fit on a old carb?


Regards

Art

[ArtJ]

Art - I would not be comfortable using hose (not even approved marine) at this location. A copper flare type led off to a valve might be ok. Regards, Hanley

Hanley
A dumb question
On my present engine, and including my spare engine, marine hose
connects directly to the carb. Since the passage block is in nearly
the same area why shouldn't we use it there as well?

Regards

Art

[hanleyclifford]

Art - You're right. We do use fuel hose but the problem in this case is that the hose would be very small and the clamps obscured from the easy inspection of a normal fuel line. I like the idea of a valve installed as directly as possible. Regards, Hanley

[ArtJ]

Hanley

Going with your above recommended valve and adapter,
Is the current diagram as below?


rethread Passage> 3/8 Nptf -> ???fitting> flared copper> ??fitting >1/8 Nptf 7010K11 valve -> 2" npt adapter -> 1/8 Npt to ?? -> hose barb > hose > hose barb > reservoir

Thanks

Art

[hanleyclifford]

Art - As they say, a picture is worth a thousand words; I'm not clear about your design but this might be helpful. We are dealing with small sizes here which is why I prefer pipe to hoses. One end of this tube could be in the carb passage and the other in a valve sitting on top of the reservoir somewhere below carb level. Regards, Hanley

[ArtJ]

Thanks very much Hanley

I now see why 1/8 in is bigger than 3/8. It refers to the line itself.

Other engines have a copper line ( standard) from the
mechanical pump to the carburetor fuel input. I am curious if this
fitting fits in the main passage block, or if it has also Nptf?

Regards

Art

[ArtJ]

As another thought:

What if the passage plug itself was drilled out using a
bit which then has a hose barb brazed to it?

The fuel hose could then directly connect to a barbed in line fuel shutoff on way the water separator.

the Carb passage would remain standard NPTF.

The separator would connect normally with a hose barb, no rethreading.

The hose would push out of the way without damage or kinking when working on the engine in tight spots.

Regards

Art

[ArtJ]

As another thought:

What if the passage plug itself was drilled out using a
bit which then has a hose barb brazed to it?

The fuel hose could then directly connect to a barbed in line fuel shutoff on way the water separator.

the Carb passage would remain standard NPTF.

The separator would connect normally with a hose barb, no rethreading.

The hose would push out of the way without damage or kinking when working on the engine in tight spots.

Regards

Art

Oops Correction: the passage would remain ordinary fine threads, not NPTF

[hanleyclifford]

Not to worry about that. I feel comfortable about opening up 3/8"NF to 1/8"NPT.

[ArtJ]

Hanley

I see 3/8 street Ells in MMI catalog,, 45 deg, 90 deg.

Could these be put into the straight 3/8 threaded passage directly
then fitted out with a standard hose barb? It seems everything would
just thread together?

Regards

Art

[hanleyclifford]

Art - Remember the 3/8" NPT refers to the ID of the passage whereas in NF the number is close to the OD of the fitting. The carb can be opened to 1/8" NPT and then any combination can be used including the short pipe set up I posted. How about using an additional Racor unit as your reservoir with a McMaster's valve on top? - Regards, Hanley

[ArtJ]

Thanks Hanley

I am getting more educated all the time. Just made a trip to Home Depot

The closest I could get was the following:

A 1/8 x 1/8 street Ell to a 1/8 nipple to a 1/8 x 1/4 reducer to a 1/4 hose barb. Longer than I would like, approx 3 ", due to reducer and nipple before barb, but possible.

Doesn't Moyer carry a barb to 1/8 NPT male that threads directly into
the carb for Electric pump usage? Maybe that could be used into the
passage block after tapping to 1/8 NPT.

Thanks again


Art

[ArtJ]

hanley

It looks like the Best option could be the below from MMI catalog?

Brass hs brb 1/8" MNPT x 5/16" barb 90

the carb passage would be directly addressed after tapping.
with the above fitting


I think the Fuel water separator takes 1/4" barbs, so maybe more adapting on that end to get to 1/4 "? or possibly force 1/4 hose onto 5/16 barb?

Then just add in line valve near Racor as you suggest.

Regards,

Art

[hanleyclifford]

Now the remaining issue becomes getting an overboard vent line to the other side of the Racor.