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I recently picked up a 58 panshovel it came with an s&s carb. I'm curious about linkerts and why they are so popular, is it just going with the period correct coolness hype or are they the best running carburetor? This is my first big twin venture so any input would be appreciated.
 

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The Super E is a way better carb, but there is nothing wrong with a linkert, kinda hard to run one on a shovel........Roach.
 

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Linkerts were SO bad that H-D only used them for a little over three decades.

Their absolute worst had to be the Model DC used on '66 Shovelheads, because S&S copied their first carbs after it.

....Cotten
 

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I always considered the S&S L Series to be a copy of the DC Linkert, The B series to be a copy of the M series Linkert, and the E Shorty series to be a copy of the Keihin butterfly....But IMO All of those S&S carbs have poorly designed transition circuits, while the Linkerts have a properly designed transiton circuit. You can easily check this out with side by side runs on a dyno, with the air/fuel ratio being checked at the same time. If you properly rebuild a M series Linkert, with quality parts, they are an excellent carb. First rule, never use anything but one of the new style floats, NOT a brass float. Second rule. pressure test the carb and manifold. Third rule, only use quality parts. Forth rule, if you have a "plumbers intake" use Enfield Racing's ferrules, but if using an "O" ring intake manifold, use quality "O" rings, and stock style clamps.

Oh yeah, IMO the CV is a copy of an SU, the Mikuni VM round slide is a copy of an Amal, and the Mikuni flat slide is a hybid of a Lectron and a Amal.

Yeah, your going to tell me how good the gas mileage is with your CV. That is because it is running leaner, and the motor is running hotter.

I've heard that there have now been changes to the S&S E series, with a different transition circuit and air bleed. I haven't seen one yet to verify it.
 

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That would be cool to have a shovel that ran good, maybe not great but good, and started nice, with an M74. Just the novelty of it. I really like my early S&S B, though.
 

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Linkerts were SO bad that H-D only used them for a little over three decades.

Their absolute worst had to be the Model DC used on '66 Shovelheads, because S&S copied their first carbs after it.

....Cotten
your sarcasm is at odds with each other...I think

still funny tho
 

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Folks,

One reason why Model Ms were replaced with the DC was that the horizontal throttledisc does not favor one cylinder over the other within a Shovelhead's super-short manifold. The higher port velocities of flatties, and the long intake tract of earlier OHVs were able to overcome the side-bias of a vertical disc.

The length of a Model M also means your right knee would be in the next lane, and its weight would require a monolithic support bracket.

Meanwhile, Pzokes wrote:
"If you properly rebuild a M series Linkert, with quality parts, they are an excellent carb."
This is true of course, but many critical parts are still not available out of a catalog, and much of what is on the general market is practically useless.
(Beware of USA-made throttleshafts that bind when the screws are tightened, venturies machined undersize, soft and raw needle knobs, etc.
And for imported parts, beware of rubber-tipped floatvalves, floats that don't float (even black foam ones), metric width needles, fixed jets drilled wrong, etc., etc., etc.

The one part you do not want to replace is the body, but often the bore is worn from a sloppy disc. The only cure is to remachine the body and fit an oversized disc and venturi. V-TWIN's oversized discs are abortions, and oversize venturies are not offered. Thus Linkerts' reputation remains marred by incomplete overhauls.

Pzokes also wrote:
"First rule, never use anything but one of the new style floats, NOT a brass float."
True, brass floats are tragic.
But beware that all black foam floats offered in catalogs and national advertizing use an obsolete, off-patent formula, and were reported to swell in Pacific Northwest USA fuels during the 2010 summer-blend season (attached).
Please note also that swollen S&S floats have been reported over the years as well, however productions after June of '08 should be safe, as that is when the latest formula became available, but not yet available in a molded Linkert replacement.

Pzokes also wrote:
"...if you have a "plumbers intake" use Enfield Racing's ferrules,.."
Also quite true..., however, you will need a perfect, pristine manifold that Enfield Racing's pre-cast seals will fit; Not only must they be a snug squeeze onto the spigots, but there must not be blemishes that will impress into the PEEK, lest it lose its miraculous re-useability. Beware that even new Colony replacement manifolds occasionally do not match spigot to spigot!

" but if using an "O" ring intake manifold, use quality "O" rings, and stock style clamps."
And the quality O-rings are the market currently are JAMES true viton offering, which actually do NOT swell three times their size in P4gas!
Beware of stock-style stainless clamps that are .030" too wide for Shovelhead (and probably Sportster) applications. They must be ground to .750"

....Cotten
 

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I've been using an old Gary Bang (I think) brass float for over 15 years now with no issues, so I don't know, maybe I got lucky.
 

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I've been using an old Gary Bang (I think) brass float for over 15 years now with no issues, so I don't know, maybe I got lucky.
jdpan!

With premium gas bouncing off of four dollars a gallon, you would have to be rich, or never ride, for your boatanchor float to not be an "issue". As much as an extra eight miles to the gallon increase has been reported when brass units are replaced.

....Cotten
 

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When I ran brass floats, I would always get a puff of black smoke out of the pipes when I shifted gears. My gram scale shows Cotton's floats being closer to stock weight than the other fuel resistant float that is being sold. It does require someone with a little mechanical competence to install. If you are a three toed sloth, or a Mongolian sheep herder you might break it. I've also noticed a little more clearance around the inside of Cotton's float, to the carburetor body. I don't know if that was intentional, but that's probably a good idea.

The S&S L series was originally designed as a race carb, but we started putting them on our street bikes. The transition circuit was not very good when this carb was designed. George Smith originally built the carb for drag racing, and it was designed to run wide open. We had to run it "fat" down low to get it to run right on the street. The B series had some of the same problem. Who remembers all the S&S carbed Shovelheads with fouled plugs? You can run the B series lean and it won't run as strong, but will get much better gas mileage. People that used to run the DC Linkerts on the drag strips used to cut down the floats to get more fuel in the bowl. Later, there was a float bowl extension that was sold. This was because the drag bikes, running at a constant high RPM would have the float bowl run out of fuel at the end of the drag strips.
 

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Pzokes!

My floats are smaller than original floats because they are machined from a lighter material. They are calculated to produce the same buoyancy, and use book spec for a setting.

Any heavier float requires trial-and-error to find a delicate deeper setting, at the expense of bowl reserve volume. Add its sluggish response, and the actual level of fuel within the bowl can vary much greater than with a light float.
A smaller ultralight float adds extra reserve to the bowl volume, and a more stable level as well.

Original floats weighed about three grams. The black molded float in my previous post weighs nine, the same as the India-made brasses.

....Cotten
 

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What prevents anyone from running an M74 (or any linkert for that matter) on a shovel?
Go back and read the first couple of paragraphs of Cotten's post, #13 in this thread. (Cotten is The Man when it comes to Linkerts)

Sure, you could make an adapter or manifold to bolt the Linkert to a Shovel, and a good support to hold it up. And sure, you could ride with your right knee cocked out all the time like the guys with the SU do, maybe extend the brake pedal out a little so you could reach it when you need to. But at anything other than WFO, more of the fuel/air mixture is directed to one cylinder than to the other because of the vertical butterfly shaft.

The shorter intake tract distance on a Shovel (as compared to a Pan) is a performance advantage if the mixture is even. But to do that you need a carburetor with a horizontal throttle shaft or a slide like an Amal.

Early Keihin's had a mismatched mixture cylinder to cylinder, but that was on purpose. HD would point the accelerator pump jet at the rear port because the EPA was taking the polution testing readings off the front cylinder (or vice versa) at the time. Most Kehin's that have been rebuilt have had this corrected.
 

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Interesting. Somehow I missed that the first read through. Trust me, Cotten's reputation precedes him and I wasn't questioning his response. Haha...
 
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