Yes, we still have quite a few bikes without EFI in our stable. And we like it that way. That is until the stock sucker wears out or gets gummed up with today’s bad gas to the point of needing a complete rebuild. That is when we decide if some sort of R&R (remove and replace) is in order. And since the stock CV carb on this 1989 Sportster was way past its expiration date, the search was on for a new original-fit carburetor.
Since a new carb is the action plan, we usually end up getting some sort of all-in-one-kit like this here HSR42 from Mikuni due to its ease of installation and its customarily hassle-free performance once its properly installed.
With one of these kits purchased, we then set out installing and riding the kit for more than 2,000 miles. And here are our findings regarding the HSR42 Sportster carb.
Mikuni started making carburetors in 1923 and has gained a stellar reputation over the years for making quality, no-nonsense carbs that just plain work. The HSR42 is no different than all those air-and-fuel mixers that came before it. The HSR series carb was designed with a precise roller bearing slide for smooth throttle control and reduced rider effort. This design also meters fuel at a positive rate throughout any throttle setting and allows an unobstructed venturi at full throttle.
The Mikuni HSR 42 has an adjustable accelerator pump, which provided us much improved throttle response over the stock unit. The HSR series carbs also possesses a high-capacity float bowl, which can prevent fuel starvation even under wide-open throttle applications. All this good stuff makes it a very versatile carburetor for all types of road conditions and riding styles from mild to wild.
Mikuni offers two different HSR42 Performance Carburetor Kits for Sportsters. One includes a special backing plate that works with the stock oval cover, and the other is for aftermarket air cleaners. Both kits work with the stock H-D push-pull throttle cable assembly so both are very easy to install.
We have found time and time again that the Mikuni is a solid-working performance replacement for the stock CV carb no matter what model V-twin Harley we have put them on. When properly tuned we have also seen frequent horsepower gains up to 20 percent with an upgraded intake and exhaust pipe. Not too shabby at all.
In short, when installing a Mikuni HSR series carburetor, you are opting for a simpler and more powerful induction system on your bike over the OE setup.
And that’s a real good thing to us.