1929-31 Schebler Carburetors

[Steve Slocombe]

The 1928 and earlier 1 1/4 inch Scheblers are assigned to named years and models in the 1928 Schebler manual reprint, and 1932 and up in the Indian restoration guides. For 1930-32 Harley Big Twins I have seen DLX45, 80,82,85,88,92 on original bikes. I know DLX 81 goes on a 1931/2 Chief. This leaves the bronze DLX 58,66 and 72 Scheblers which are not particularly rare. I have been using them on 1930 Harley VLs, but recently found a couple with fine threads for the air intake screws, where Harley used the coarse No. 10 x 24 tpi screws. By inference they must be for Indian Chiefs, as they are not 4-cylinder, and most of the small twins were using one inch carburetors at the time. I asked the Indian experts at Oley but no-one was sure. Are there original bikes out there with DLX 58,66 and 72 Scheblers so we can assign these to particular years and makes? The DLX 61 also has fine threads and is still found at swap meets.

[20scout]

Hi Steve,
The carb on my original 29' chief is a DXL36 if that is of any help.
Regards,
TR

[T. Cotten]

Steve!

My first DLX58 has appeared, and it is also the first carb that I have encountered with #10-32 threads (that appear un-boogered, anyway).

One surviving countersunk airhorn screw is also fine thread,...a pic is attached for identification. I think it was brutally shortened.

And yes, it came off of a Chief project.

The half-dozen DLX 36's that have crossed my benches were all #10-24, as have been all bronze DLXs before this one.


....Cotten

[39ChiefBonnie]

1929-31 Schebler Carburetors

So can anyone shed any light on what they think the correct carburetor for a 1930 Chief would be. The Linkert Carburetor site says DLX-81 (for 1930-32 Chief) and this is the only information I've been able to locate. Any detail greatly appreciated. Thank you.

[Steve Slocombe]

The pot metal DLX 80 was used on later 1930 VLs, so I'm guessing the DLX 81 is pot metal too. Indian stuck with them through 1940, while Harley went to the brass Linkert M2, M21, M31 etc starting in 1932. I think the Linkerts are superior to the pot metal Scheblers, and there was an active retrofit program in place in the 1930s. Today the Indian guys with 1930s bikes are often fitting Linkerts, and the military M88 Linkert models I literally used to see in bucketfuls in European swap meets are pretty well mined out. Some Australian owners have reported DLX 58 carbs on 1930 VLs, and I've seen photos of 1930 VL Police bikes with the air intake cap rather than the regular 1930 air intake. If you look at the Harley parts book, you'll find air intake screws 1408/9-28 for 1928 to first 1930, which are not the same as the 1408/9-29 used later. My guess is that the earlier screw has the fine thread and is associated with the cap air intake, while the later screw has the coarse thread and is used later 1930-1934.

[T. Cotten]

So can anyone shed any light on what they think the correct carburetor for a 1930 Chief would be. The Linkert Carburetor site says DLX-81 (for 1930-32 Chief) and this is the only information I've been able to locate. Any detail greatly appreciated. Thank you.

That seems to be the consensus, 39ChiefBonnie!

(That doesn't mean the rest of that site's listings are accurate..)

....Cotten
PS: Steve!
The DLX58 is now usually associated with SuperX, and yet another one is on my bench with #10-32 intake screws.

PPS: Folks, the superiority of the later Linkerts rests upon two innovations:
The HS needle guide cast upon the bowlstem, and the enigmatic idle bleed slot.
(I have a remedy for the needle guide problem on all DLXs. The idle bleed mysteries prevail.)

PPPS: Where did my 2006 attachment go?

[Peter Cooke]

"Some Australian owners have reported DLX 58 carbs on 1930 VLs, and I've seen photos of 1930 VL Police bikes with the air intake cap rather than the regular 1930 air intake. If you look at the Harley parts book, you'll find air intake screws 1408/9-28 for 1928 to first 1930, which are not the same as the 1408/9-29 used later. My guess is that the earlier screw has the fine thread and is associated with the cap air intake, while the later screw has the coarse thread and is used later 1930-1934."

Interesting. My bronze DLX72 that came on my 31V has 1 screw hole with #10x32tpi and the other with #10x24tpi. I'm assuming they were both originally #10x32 as the hole with #10x24 clearly looks like it's had a tap run thorough it to change it and it's not square to the surface. Given that I can't find the #10x32 air intake screws I'm thinking along the lines of helicoils in both to get good #10x24tpi threads.

Apologies for getting off topic.

[Steve Slocombe]

Interesting Peter, and typical of Harley to use up last years parts on export modals. And how did they put in that idle slot Tom, I've never figured it out?

[T. Cotten]

And how did they put in that idle slot Tom, I've never figured it out?

Me neither, Steve!

Even today, nobody makes an endmill that small that's long enough, and any 'punch' would have been just as phenomenal.

The only clues we have are the mistakes.

....Cotten
PS: Back to Scheblers, George Yarocki once reported he had literature that cited potmetal production starting June 1929.
Wish we had a copy...

[Steve Slocombe]

Thanks Tom and your pictures make it look like they put the slot in first and then drilled the idle holes. My sheet metal guy told me you can't cut a slot thinner than the material you're cutting, yet Linkert did this 85+ years ago without lasers, spark erosion, or diamond coated saws. Respect!

[T. Cotten]

I really don't know, Steve,...

If the slot was cut first, a couple of those should have been scrapped.
Drills would also want to 'walk' to the slot, so the M51s imply they were performed first.

We are talking about machining through about thirty thou (3/4 of a mm) of bronze, probably more if the bore was finished later.
(Lack of burring and punch 'distress' implies that. Plus original bore diameters are just too consistent!)

So, can we make Scheblers better with a slot?
The open 'area' is critical, but these two Bonne (or M352 for 80" Chiefs) slots imply a Schebler could be opened up if the small hole is small enough to begin with.

....Cotten

[T. Cotten]

A little help, Please Folks!

Can anyone look up the float setting for late '29 to '32 or so potmetal Scheblers in 'Harley Davidson Operation Maintenance & Specification 1911 thru 1930' for us?

Surely there is one?

Many thanks in advance,..

....Cotten

[aumick10]

Tom,
I don't see the float settings in that manual, only needle settings.

[T. Cotten]

Tom,
I don't see the float settings in that manual, only needle settings.

Many thanks for looking, Mick!

Doesn't a lack of float settings seem strange, Folks?

HX Scheblers had settings, bronze DLX bowls had settings, and the late 'long' potmetal bowl had a setting spec,
but none for the very different "short bowls" in between?

I guess it didn't matter,.. much.

....Cotten
PS: If the 'short' bowls follow the form of the others, then I would predict a setting of 3/8"!

[aumick10]

If all else fails, whatever works is the setting.