Need replacement carb for Bendix

[Wreckman]

Need a carb for my 56 what should I look for? It has a Bendix on it and it needs replaced.

[jdpan]

I asked a similar question a while back and the general concensus was Linkert. Mine works flawlessly but the milage could be a little better, thats my only complaint.

[amiabledave]

Why do you need a carb? I have 4 M-74's in the garage, but I run a Zenith Bendix that I installed over 10 yrs ago. Nothing was wrong with the Linkert and agree with jdpan. I just get a better response with the accelerator pump...

[Cotten]

AmiableDave!

Linkerts (and Deluxe Scheblers) have their own "accellerator pump", it just doesn't have any soft parts or moving hardware to wear out.
Instead of raw gas, it gives a shot of emulsion:

1943 Armored School Handbook

ACCELTXT.jpg (104.66 KiB) Viewed 1079 times

Your "better response" is either subjective, or your Linkert needs work!

....Cotten

[john HD]

wreck,

i tried 4 different carbs before i settled on a very nice M-74b, had it professionally rebuilt and installed one of cotten's floats.

i am really happy with how it performs and how easy the bike starts.

john

[amiabledave]

Cotten!!

I'm willing to be enlightened. And if I'm wrong, I have just learned something....

What emulsion (a mixture of two or more immiscible (unblendable) liquids) are you/the article talking about? What 4 holes at the base of what nozzle is the article talking about? And where is the gas reserve at, besides the float bowl? Also Gas (that vaporize at temperatures below the boiling point of water. That's why if you spill gas on the ground, it evaporates) and Fuel (Diesel or other fuels that vaporize at temperatures above the boiling point of water ) are to different things and the article is talking about fuel.......

The throttle cable moves the throttle disc, that's all...and the Linkert only operates on engine vacuum. Open the throttle more and it draws/sucks in more gas. That's your accelerator pump.

That's the beauty of the Linkert, simplicity and few moving parts. On my Bendix, when I crack the Throttle with the engine off, You see a stream of gas come out...Not so with the Linkert....

[Cotten]

AmiableDave!

The emulsion is air-in-fuel, a bubbly froth, the first step to atomization when it sprays from the nozzle spigot into the venturi.

The holes are varied on nozzles for various models (By '52 or so, OHVs returned to Schebler's original 5-hole pattern.):

HDNOZZLS.jpg (91.31 KiB) Viewed 1060 times

The volume of the void on the outside of the nozzle determines the size of the charge expelled, and it was dramatically increased as the venturi bores increased.
The reserve is the bowl itself, which is considered its own circuit in the Armored School literature.

If the venturi is loose in the carb body, and/or there is wear around the nozzle spigot, the ability of motor vacuum to pull the charge efficiently is compromised. Most carb "overhauls" ignore this interface, giving Linkerts a bad rep.
Furthermore, modern huge and heavy floats rob the bowl of reserve volume, causing the charge to be replaced slowly.

With everything in order as it was designed however, the carbs are the stuff that legends were made of.

....Cotten

[amiabledave]

Cotten!

If you call emulsion air to gas ratio I'll agree to that. I think of it to 2 liquids...

I just took 1 of my Linkerts apart to see if my venturi tube ( book term is nozzle) had holes in it. Well the nozzle is crusted in and will take a good soaking and work to get it out. (Do all have holes or none like your far right?) ......I only rebuilt the one that was on the bike before I bought it, I could not remember or never noticed the holes. Also I can't remember if I took it out. Has to be over 30 yr ago.

When the article states the reserve is just outside the 4 holes of the nozzle and when the throttle is snapped it makes use of the gas, it still is Vacuum dependent first. It doesn't have an accelerator pump that shoots gas up

Although both are vacuum dependent, I would say and I'm not an engineer, when the throttle is snapped, with an accelerator pump, gas is sent out 1st and vacuum drags the gas in...Without a pump, vacuum sucks the gas out.... and hence a delay if ever so slight.

Don't get me wrong, the linkert was state of the art back then. The article you pasted is from 1943, and the last Linkert made was 65...Then carbs came with Accel. Pumps, which are dated with the injecton system..

So getting back to what lead us to an enlightened forum for me, is WRECKMAN, I like to see gas squirt and like the gas mileage. If your a traditionalist, go Linkert. Both will get you down the road and that's what counts....

[Cotten]

AmiableDave!

Time better march on, and a design that was used ca.1912 to 1965 damwell better have been superseded by improved technology!

And indeed it has: fuel injection.
How can you settle for anything less?

In other words,
You are either into old stuff just because of what it was, or you enjoy re-inventing the wheel.

That's OK, too.


....Cotten
PS: The far right nozzle was turned around to hide the holes, sorry, the pic was taken for other reasons.

HDNZZLS.jpg (83.44 KiB) Viewed 1026 times

Your description of vacuum dependence is exactly why the nozzle system has its own unique advantages. Yet most of us only care about zero parts to wear out, leak, break, or dissolve in the fuel.

[john HD]

cotten,

what are the spacers in the left photos?

what were they made of?

were they a part of the nozzle or a seperate part number?

john

[hydra74]

seal from peek ?

hydra

[Cotten]

Yes, PEEK of course.

This was a study of the different nozzle heights; No such seals of such heights were ever produced, yet the spigots appear to require them to place the opening in the center of the venturi: Just another question for which I have no answer.

....Cotten

[Scrap]

The Linkert on my 57 was flawless, however, in the 1970's, during the gasoline crisis, many stations were rationing fuel and many were closed on Sunday's. Returning from the races at Laconia one summer, the narrow fatbobs on my bike did not have enough gas to get me home. I had to drain residual fuel from the hoses at every station I passed so I could get home. I wanted better mileage. I saw an ad in Big Bike, Branch Flowmetrics was selling a bolt on Mikuni kit complete with a Panhead manifold and the ugliest air cleaner I ever saw. That guy knew so much about Mikuni's, Mikuni bought his company. What a great setup....mileage improved by 40% and the bike started and ran every bit as good as the Linkert....it didn't look like it belonged, but it sure did the job. I dialed in the right jet (it came with a selection) and never touched it again. If mileage is an issue, you might consider trying to find one....I see the manifolds for sale here and there. If I'm capable of attaching a photo, you can see mine, sort of, back in the day.

[Wreckman]

Scrap,
Thats a cool pic. Do you still have that bike? The good ol 70's. Would love to go back. Had the same Hayden oil cooler on my sporty. There was a shortage of gas but never beer.

[Scrap]

Scrap,
Thats a cool pic. Do you still have that bike? The good ol 70's. Would love to go back. Had the same Hayden oil cooler on my sporty. There was a shortage of gas but never beer.

Yes, I still have the bike. I retired it when the rubber mounted 5 speed was introduced in 1980 (hard to believe that shovel is now 30 years old). Lots of long distance trips back then, I got fond of comfort. The pan started out as a Massachusetts State Police bike then a chopper with the usual 70's stuff, king queen seat, raked neck (if only I knew then what I know now) extended front end, no front fender, foot pegs, mouse trap eliminator...eventually it morphed into a mongrel with foot boards, fender re-attached with muffler clamps cause I milled off the fender mounts, (my first mud puddle without a fender made me question my sanity) solo seat with the pogo and I added buddy springs....that seat with the springs was ridden sometimes with hemorrhoids and I never felt a thing. It's being reincarnated at the moment. Paughco springer, PM brakes, new wheels, pipes, more of a hobby than a ride, but hell, being near a bike thats over 50 years younger than me is as good as dating a girl half my age....and like they say....your as young as the girls you feel.