The S&S carb we had on our `79 FL over 20 years ago was worn out. The previous owner, who must like to tweek-out and tune his carb with a rat-tail file, had molested it beyond repair. No matter what we did, the poor damaged Super B just never operated correctly.
When we decided to swap out the carb. We wanted to go with a slide-type carburetor instead of a butterfly-style that the S&S had. After looking around for options, we went with Rivera-Primo's Mikuni HSR 42 kit, which was designed specifically for Shovelhead engines.
The kit comes complete with everything needed to install the Mikuni carb including a manifold, mounting brackets, hardware, and a specially designed K&N air filter with chrome cover.
The installation was very straightforward and with the included instructions we had the new carburetor on in less than 90 minutes. Our Mikuni came from Rivera-Primo pretty well set up for this application, because it needed only a minor idle adjustment to get it tuned right.
With the HSR 42 bolted up, the bike seemed to have much more power and a snappier throttle response. If you are looking for a true performance upgrade on your Shovel, then we would seriously suggest considering this kit.
01 The old Super B had been...
01 The old Super B had been destroyed by its previous owner, so it was time for a change.
02 After we removed the old...
02 After we removed the old carb we pulled off the manifold and cleaned the intake ports.
03 The new Rivera-Primo manifold...
03 The new Rivera-Primo manifold and seals were installed.
04
05 The top case bolt was...
05 The top case bolt was swapped out for a longer unit, which holds the carb brackets.
06 We installed the throttle...
06 We installed the throttle cable to check for length. Rivera-Primo suggests using both a throttle and return cable, but we chose to live dangerously with just a single cable set up.
07 The HSR 42 carb was installed...
07 The HSR 42 carb was installed onto the manifold and tightened down.
08 The brackets that hold...
08 The brackets that hold the carb in place were bolted up to the longer case bolt.
09 The brackets bolted directly...
09 The brackets bolted directly onto the back of the air cleaner, which is clamped to the front of the carburetor, holding it in place.
10 The chrome air cleaner...
10 The chrome air cleaner cover was then installed with a single bolt.
11 We chose to locate the...
11 We chose to locate the choke knob on the back of the air cleaner with an L-bracket that we fabbed up.
12 Once the carb kit was...
12 Once the carb kit was finished being installed on the bike, we reinstalled the throttle cable and adjusted the slack.
13 The new Rivera-Primo Mikuni...
13 The new Rivera-Primo Mikuni carb kit has been successfully installed on the bike. Lurking under the chrome cover is one simple and effective carb swap.