Issue link: http://trailridermagazine.uberflip.com/i/1540850
October 2025 35 It's no secret that we're big fans of Lectron Fuel Sys- tems carburetors here at Trail Rider. So much in fact that at present we've got over a dozen Lectrons in our fleet fi ed to modern and vintage alike. What do we like about Lectrons so much? To sum it up, the simplicity of the design, having no ny jets to clog, and their "set it and forget it" approach to tuning. Yes, they are a bit different, but once you understand how they work, the process becomes easy since all the tuning is done with the metering rod or needle, just like a conven onal carburetor. Although this project was a bit out of the ordinary for Lectron, they make odd applica ons such as this easy by providing a form to fill out to include all the measurements of the carburetor that will be re- placed. A er emailing all measurements directly to Lectron, we received a new Billetron Pro 38 within less than 10 days. In order to simplify the process, Lectron also offers its carbs with the proper thro le cable and thro le assembly. I'm happy to report that the new carb fits like factory with zero issues during installa on. How does this beast run, you ask? Well, right out of the box, our ATK fired within three kicks cold and one kick when hot. Other than a minor metering rod adjustment, the bike runs crisp and clean from idle on up. In fact, this bike could idle all day and s ll not load up. Delivery is clean and linear with typical big-bore 2-stroke torque. What's interes ng is unlike most big bores, the Rotax 406 has very li le vibra on and is easy on the hands and feet. As men oned above, in stock form, the clutch pull was ridiculous, and this is coming from a guy who s ll rides and races vintage bikes. In looking to re- duce the effort to disengage the clutch, we elected to purchase a Magura HYMEC (hydraulic/mechan- ical) clutch kit from Keith at American Dirt Bike. -ADB is the source for ATK and is a tremendous resource if you're considering an ATK project. ADB has engineered a custom pull rod for the hydraulic cylinder that makes conver ng a Rotax to a hydrau- lic clutch a breeze. The installa on takes as much effort as replacing a clutch cable. This simple mod- ifica on makes a world of difference when riding the bike. The pull is about equal to a Beta hydraulic clutch, making trail riding so much more enjoyable. Lectron Billetron Pro 38 carburetor Lectron Billetron Pro 38 carburetor