The History Of The Rivera SU Carburetor

Rivera-SU-CarburetorSU Carburetor  History: Back in the early 70’s, Rivera got its start when Mel Magnet (The Founder of Rivera Engineering) took off SU carburetors from some British cars and did some magic to adapt them to Harleys. In 1974, Custom Chopper Magazine sponsored the “Search for King Carb” shoot-out between all the top carburetors back then to find the “King of Carbs”. And guess who won hands down? The Rivera SU. Fast forward forty years and Rivera Primo Inc. is still making the SU to Rivera Primo standards.

Applications: When Rivera started making the SU back in the 70’s, there wasn’t any Evo’s or Twin Cams even on the drawing board yet, so all the kits we made were for Iron XL’s, Knuckles, Pans and Shovels. Well, Rivera Primo still make all those kits and on top of that now have kits for all Evo Big Twins and Twin Cam applications.

The New SU Carburetors For Evo Sportsters: The company has been asked by many customers to create a kit for Evo XL’s (Sportsters). Available immediately in Cast finish (Ref: 1041-0062), polished finish (Ref:1041-0063) and chrome finish (Ref: 1041-0064), the new SU kit for Evo XL’s fits all Evo style Sportster models!

About Rivera Primo®: The company, as mentioned above, started life under Mel Magnet’s guidance as Rivera Engineering® in 1973 and then Mel added Primo® Belt Drives into its fold in 1977. After nearly 35 years living life under two banners, the two companies were merged under one name, Rivera Primo Inc®. Rivera Primo celebrate this year its 40th anniversary.

13 Responses to “The History Of The Rivera SU Carburetor”

  1. 1 Rodent Apr 16th, 2013 at 10:10 am

    S U means Seldom Understood !

  2. 2 LenNY Sinnet Apr 16th, 2013 at 10:15 am

    Great carburetor, Runs great, classic looks and easy to
    tune. Well worth trying you cant go wrong.

    LenNY Sinnet

  3. 3 Bruce Apr 16th, 2013 at 11:18 am

    I use one and it’s my 3rd one.

  4. 4 Greybeard Apr 16th, 2013 at 3:43 pm

    Bruce, we’re seeing a pattern here. ;o)

  5. 5 Jim Nasi Apr 16th, 2013 at 3:58 pm

    I have had an SU on my 81′ Shovel forever…….. love it , great carb.. and yes Rodent, they are Seldom Understood

  6. 6 Bleeding Ears Apr 16th, 2013 at 4:44 pm

    Back in the day when Carl Morrow ran Carl’s Speed Shop in Whittier, CA he had a standing order with all of the local wrecking yard that whenever a British sportscar was totaled to call him and he would send his employee; Mel Magmet to pull the SUs off of it.

    I like LOUD pipes!

  7. 7 morpion Apr 16th, 2013 at 7:15 pm

    great carb and easy to tune

  8. 8 Rogue Apr 17th, 2013 at 7:18 am

    I used them back in the 70s as well and once I figured out how the numbers of the jets and needles worked with the help of a German mechanic I knew things went well.
    There was a junk yard next to the clubhouse and they saved all the SU carbs for me, I should note most were 3 carb set-ups But only the center one had a low speed circuit so people who bought them and did not know that did have problems and of course blamed it on the carb instead of themselves.
    Those of you that have seen photos of me and my motorcycle “CRAZY HORSE” on the Fall 1970 issue of Colors magazine you will note it has a SU carb on it.
    Through the years refinements have been made to it and it does work very well. Just have to remember to add some oil once in a while and the type will also affect how fast or slow the slide works. Fine tuning tricks for different parts of the country and temperatures.


  9. 9 DAYTONA DONNY Apr 17th, 2013 at 8:21 am

    I have been using these carbs on bikes since the late 70’s ..and still offer rebuild service here in Daytona ….properly set up these are 50+mpg..and lots off throttle response ….Glad to see the update of the manifolds for the later models

  10. 10 Bigalyts Apr 17th, 2013 at 8:28 pm

    Well Daytona Donny, you are the only one that said what I want to gear: “Great Throttle response and 50+ mpg”. however I run a Mikuni and it has the response and the CV has great dependability and the S&S are just the Old faithful, doesn’t make much HP but has always had nice looking Air Filter Kits to wake the Engine up Cosmetically. Does the SU carbs make HP? That’s all I care about, cause the Look of the Carb isn’t for all Bikes cosmetically..

  11. 11 Paul Apr 22nd, 2013 at 11:01 am

    I’ve been using them forever. Like Donny said, I get 50+mpg on both of my 80″ ’50s , and my dad’s 88″ ’49 does just as well. The tickler is great for kick start bikes too. One kick EVERY time. And the fact that they are Seldom Understood means there are plenty at the swap meets for cheap!

  12. 12 Leesure Apr 22nd, 2013 at 3:14 pm

    Nice old carb, the first CV style carb, proven performance. Glad John and Ben are keeping it around.

  13. 13 Ben Kudon Apr 23rd, 2013 at 7:53 am

    Just to keep the record straight, Mel Magnet (RIP), never was an employee of Carl Morrow or Carls Speed Shop. Mel was taking SU carbs off British cars for years and went to England himself to wrap up the exclusive distributor ship which we still hold to this day. Incidentally, we have a rebuild service for SU’s where for a modest cost, we will bring them back to factory specs if you send in your carb to our Whittier, CA facility.

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Cyril Huze