Linkert M741-1 rebuild

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Figured I go with a new thread on this carburetor that came with my 101 Scout. I was going to send it away (and I may still !) but after asking Cotten who he might suggest, he suggested I go for it myself, so here we go. (full disclosure.... I may have failed as many times on carburetor rebuilds as I have been sucessful, but live and learn I say.)

Here's what I am starting with, a dirty old 741 with a cork float that was mostly dust:


First thing I discovered is that the bowl appears to be Schebler, it's brass and doesn't seem to have a replaceable needle seat?


The float needle is still there, but without being able to replace the seat I'm wondering how to get a good seal?:


Then the low speed needle isn't connected to the adjuster knob, broken?


The throttle disc with a little light showing, and the shaft is actually not wobbly at all:


And finally, not sure if this is a plug or is it a jet? Either way, going to take some finagling to get it out of there:


As I said, it's really, really dirty and I can't get the discs out so I'm still working on disassembly/cleaning.

[T. Cotten]

Your first big problem, Harry,...

Is that is a pre-'29 Schebler bowl assembly, bowlnut included.

It could be 'convinced' to work, but you are better off trading it to somebody who needs it more (unless you want to go early 101 "correct" some day), and putting together a "common" Linkert sidebowl assembly.

The HS needle is also Schebler, but probably would "run". (You are going to want to put the LS spring collar beneath a good spring, not above it... Note that it seems to be the proper "fat" one,.. what's left of it.)
The frozen and boogered gallery plugs, and all the other fasteners as well, come out easier with focused heat upon the fastener only.

Welcome to my Hell, Harry!

....Cotten

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I got all the little galley plugs out except for one, not the ugly looking one in the picture above that sits in the bowl, but the one accessed through the flange on the throttle side...it was really buggered up and sits way down in there. But it looks like a dead end to the chamber where the little idle slot lives and another larger plug, so I left it in (drilling it out would probably be my only remedy).

So it’s now soaking in Chem-Dip overnight!

I’m also curious about that Schebler HS needle, if I go back to a Linkert needle will the seats be different?

[T. Cotten]

You have little to lose, Harry!...

But your patience;

Lest then you forfeit.

We all need more of that right now.

....Cotten
PS: My primary 'chem-dip' is dime-store white vinegar.
The HS needle angles and seats were quite similar, but somebody would rather have your needle knob more than a Linkert, as you, yourself might someday; What model is your 101?

Remembler "dime stores"?

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Remember "dime stores"?

I kinda miss them! Thanks for following along Cotten!

Oh ...this 101 is a 37 c.i. version.

[T. Cotten]

The original M-741 main jet would be sized for a 30.50" engine, and too small for safety with your 37". The power needle would be out of range.
Just a guess: .048", pretty close to an original H-D #0 or #11 (both 1.25mm or .0492").
Can't find one? The very common H-D #1 used in the M-88 is .052". I've soldered jet holes shut and re-drilled; try to maintain the original tapered entry to the hole.

How to identify a Linkert SV bowl: it has a threaded brass hex cap covering the needle & seat opening.

I'm confused, Kitabel!

The M741 series had no fixed jet, and the main nozzle was the same #102618 as others.

(Sorry that's an Indian number, but I don't have the MOCO's equivalent handy, yet...)

Good thing they are so forgiving, huh.

...Cotten

[kitabel]

Your X-ray vision tells you that it's a plug (the OP posed it as a question)?
Mine isn't that good.

[T. Cotten]

Similar M841s had fixed jets, Kitabel!

And "closed" HS needles like an M88, M17s, and other military models, but not the M741 and M741-1.

(My factory blue-print specs five gallery plugs, but then it declares an impossible 7/16" float setting!)

That plug is for a drilled gallery to connect the LS needle "well" to the rest of the idle circuit.

...Cotten
PS: Even an auxillary jet shouldn't be higher in the bowl than the HS needle seat.
PPS: A curious note: The earliest use of an auxillary fixed jet (upon a production American motorcycle) seems to be upon some Schebler 1940 DLX130s.
(I have encountered a few, and as many without.)
Anybody know of any others?

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Soaked overnight in Chem-Dip and it looks better, outside:



and inside:



I should mention I had no problem getting the venturi out... there wasn't one in there!

Now to make a list and order parts, gonna need bowl, float, needles, nozzle, venturi, throttle and choke plates, throttle and choke shafts, throttle shaft bushings, and some odds and ends like new galley plugs and tiny springs for the detent balls for the knobs. Good thing labor is cheap!

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I also understand that with a Linkert on a 101 Scout there is an issue with the bowl being too close to the cylinders and potentially causing the gas to boil. It may be the reason someone in the past put this Schebler bowl on this Linkert? This being a 37 c.i. I’m not certain this will be a problem, we shall see! George Yarocki made some spacers in the past, so if the Linkert bowl is too close I can either use a spacer or see if I can use this Schebler bowl.

[T. Cotten]

It may well be the machine's original bowl, Harry!

The shapes are so similar that it would be of little advantage over a Linkert bowl.
(And the distance from manifold flange to bowlstem axis is pretty identical for DLX63 and M741-1, too.)

For your replacement parts, I would suggest an Indian-only supplier. Seriously.
Although your borewear looks only "typical", without honing and then fitting an oversize disc and venturi (not readily available), there will always be daylight.

Graciously, the disc never operates closed anyway.

....Cotten
PS: Please note the difference between these Schebler bowls: The bowl cap is level with the top of the bowl for many 1¼" HX and Type A DLXs, on the right.
(DLX63 on the left; sorry I forgot the photo credit..)

PPS: If your bowl is boiling, you've got other problems!

[T. Cotten]

Any luck, Harry,...

Finding a 13/16" venturi?

http://www.jerrygreersengineering.com/catalog.php lists only a 3/4" under their M741 listing, but there is 100257 listed for Scheblers, and would function the same as the M741-1 venturi (assuming it fits your particular body.) The only difference is the shape of the air correction chamber, which matters little if any at all.

(Caveat: I order often from Todd, but never yet a venturi.)

...Cotten

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Cotten, I ordered a 3/4" from Greer's... will I notice any difference?

[T. Cotten]

Cotten, I ordered a 3/4" from Greer's... will I notice any difference?

I 'spose it depends upon your riding habits, Harry!

(If you are a very hefty boy, go small; If you want to merge with highway traffic, go bigger.)

I'm certain Greer's would let you exchange it easily.
There is some confusion as to the original DLX63 spec, since the extinct Indianmotorbikes.com spec'd 3/4" for the 45", and 13/16" for the 37".
That's a signifcant difference for small bores, and 'counter-intuitive', too!

I have encountered one M741-1 with the tiny venturi; Most had 13/16", as I believe your original Schebler had..

...Cotten

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I'm certain Greer's would let you exchange it easily.

Cotten, seeing as how I'm not hefty, but I'm not planning to race, either, yet there's lots of hills here.... I guess I might be happier with 13/16. But Greer's doesn't show it... in fact the only 13/16" venturi for a 1" carburetor that I can find with a quick search is one that goes to the XA Harley... and it has two different part numbers, for L and R. Will a Schebler venturi go in an M741 if I can find one? Thanks for the heads up, with a 37c.i. version I already have an unnecessary inferiority complex!