• Lectron Billetron Mini carburetor for 85cc two stroke dirt bikes

BILLETRON Carburetor for 2-Stroke | Quick, Responsive, & Simple (25mm-29mm, 38mm-40mm)

BILLETRON Carburetor for 2-Stroke | Quick, Responsive, & Simple (25mm-29mm, 38mm-40mm)

$649.00
$649.00
Shipping calculated at checkout.

For Riders Who Want

The BILLETRON delivers smooth, predictable power through a billet-machined body and simplified dual-circuit fuel system. Designed for riders who want real performance without constant tuning, it features our proprietary Xcelerator metering rod and high-flow power jet. It’s refined, reliable, and built for the ride—not the toolbox. Performance made simple.

Works with majority of OEM cables

Common Fitments include:

  • KTM 65 SX, 85 SX (25mm/29mm)
  • YZ 65, YZ 85 (25mm/29mm)
  • YZ125 & YZ125X
  • YZ250 & YZ250X
  • KTM 125cc, 150cc, 200cc, 250cc, 300cc
  • CR 125, CR 250, CR 500
  • RM 125, RM 250, RM 500
  • KX 125, KX 250, KX 500
  • Beta 125cc, 250cc, 300cc
  • Sherco 125cc, 250cc, 300c

Many more not listed. Please see 'Compatibility Chart' below for full list.

Includes

Each kit comes with the following;

  • (1) BILLETRON Carburetor and setup for your vehicle
  • (2) Lectron Stickers
  • (1) Tuning and Installation Guide
Description Features + Compatability Chart Specs FAQ
BILLETRON Carburetor for 2-Stroke | Quick, Responsive, & Simple (25mm-29mm, 38mm-40mm)

$649.00

Bolt-on performance without the hassle.
The BILLETRON 2-Stroke carburetor is designed for riders who want consistent, smooth power with minimal tuning. Whether you're building up an 85cc or running a 300cc, the BILLETRON delivers excellent throttle response, reliable performance in changing conditions, and a simplified setup that just works — ride after ride.

Available in 25mm and 29mm for smaller-bore engines and 38mm and 40mm for full-size two-strokes, each size is optimized to match your engine’s displacement and powerband.

🏁 Who It's For:

Riders who want no-hassle performance, smooth throttle control, and strong gains over stock — from 65cc two-strokes to full-size trail and MX bikes. Ideal for anyone looking rideability and reliability without frequent tuning. Common applications include; KTM 65 SX, 85 SX, 125cc, 150cc, 250cc, 300cc, Yamaha YZ 65, YZ 85, YZ 125, YZ 250, Honda CR 85, CR 125, CR 250, Kawasaki KX 65, KX 85, KX 125, KX 250 and many more!

Xcelerator Metering Rod

Provides a burst of fuel enrichment when ‘whacking’ the throttle for instant throttle response in all RPM’s. This innovation is a leap in metering rod technology by sustaining the hassle-free, no jetting benefits, while leveling up performance and throttle response. No compromise, just power made easy.

Power Jet System

Adds external adjustability of fuel for wide-open throttle positions. Fine tune your top end for increased power without sacrificing midrange - Ideal for racing and high-speed performance.

Tailored Bore Design

Unlike one-size-fits-most OEM carbs, our bore is precision-tailored to match your engine's air volume for sharper throttle response and better power delivery.

It's like a well fitted suit vs one from your dad's closet - mass applied sizing doesn't cut it.

Avoid the pitfalls of generic carbs. Get fitted.

Redirect Slide Ramp

Designed exclusively for our PRO-SERIES & BILLETRON carburetors, this unique slide design does more than control throttle - it redirects airflow to sharpen the fuel signal, delivering quicker, cleaner throttle response and more consistent power delivery across the rev range.

SafeDrain Overflow Bowl

SafeDrain is Lectron’s integrated overflow control system engineered to protect your engine from the complications of fuel overflow in the most demanding conditions. Whether you're navigating steep climbs, hammering through vibration-heavy terrain, or transporting a hot bike after a ride, SafeDrain gives excess fuel a clean exit path and enhanced geometry for improved sealing.

By combining overflow redirection with added venting for incline and decline situations, SafeDrain Bowl ensures stable fuel pressure and consistent performance where other systems fail. It’s peace of mind built into the bowl — no tuning, no fuss, just protection you can trust.

… …

FAQ

Will the BILLETRON work with my OEM Cable?

Yes. The BILLETRON products will

What's the difference between Lectron carbs and stock/OEM carbs?

Lectron carbs are built for riders who want simplicity without compromising performance.

Unlike stock carbs that rely on jets and constant tuning, Lectron uses a metering rod system that automatically adjusts fuel delivery based the conditions around you (elevation, temperature, humidity, etc..) . No jets to swap. No guessing. Just ride.

Here’s what sets us apart:

  • No Jetting Required – Adapts to changes in altitude, temperature, and mods automatically.
  • Smooth, Predictable Power – Strong bottom-end and midrange torque with linear throttle response.
  • Fewer Parts, Less Tuning – Simpler design means less time wrenching and more time riding.
  • Built for Performance – Whether you're racing or trail riding, you get better performance without the hassle.

It’s the performance you want, with the simplicity you’ve been missing.

What's the difference between the PRO-SERIES, BILLETRON, and H-SERIES?

Each series is designed for different rider needs and budgets:

  • PRO-SERIES: Our top-tier carburetor. Fully billet-machined with features like the Torque Jet, Power Jet, Xcelerator metering rod, internal fuel routing and a bore matched to your engine size. Built for serious riders who want maximum performance and tuning flexibility.
  • BILLETRON: Still billet-machined, but simplified for the rider who isn't looking to tinker with fine tuning. It uses just the Power Jet and Xcelerator rod for a more linear, predictable power-band but still provides excellent acceleration. Great for riders who want performance without constant tuning.
  • H-Series: Cast aluminum and fixed at 38mm, this is our value option. Simple to install, easy to tune, and ideal for riders who want better top-end power without breaking the bank.

All three perform great — it comes down to how much adjustability and performance you want, and how much you're riding.

Will the carb come pre-tuned?

We have over 50 years of experience with tuning carburetors. We setup each carb to a fundamentally determined setting based on information you provide to us. Your carb will be very close or spot on when received. With that said, varying factors like the bikes condition, wear, maintenance, oil ratio, and age of fuel can have an effect with tuning. We suggest a simple, slight tuning at install to achieve max performance and preferability. Once you set it, forget it. Enjoy no-hassle.

What if I need help with install or tuning?

No problem - we've got you covered. Our dedicated support team has extensive experience tuning and installing Lectron carburetors across a wide range of bikes and riding styles. Whether you're working through your initial setup or fine-tuning for specific conditions, we're here to help. Reach out anytime - we'll make sure your carb is dialed in and your bike runs like it should.

Customer Reviews

Based on 26 reviews
92%
(24)
8%
(2)
0%
(0)
0%
(0)
0%
(0)
100.0
100.0
C
C.H.

Excellent

E
Elias
Well worth it!!

After rebuilding my son's built Kx85, I noticed that the carb was dragging. Even after rebuilding it, still dragged a little. I learned about Lectron and how the carbs don't have jetting. Ordered one and wow!! It brought this bike to life! The throttle is snappier, idle is excellent and the powerband increase is awesome! My loves it and says it's a difference of night and day. Definitely recommend it. Thank you Lectron!!

G
Gabe
Consistent reliable fun

We bought our first Lectron in January of 2020 for my sons 65. Since then weve purchased 2 more and ran them on all of my sons 2ts - from 65,85,105 & now on to the 125. Weve logged tons of hours on our H and HV series Lectrons and as of recent, we also have a decent amount of time logged on the Billetron 38 installed on a KTM 125XC. Aside from being a super trick looking piece, the Billetron offers simplicity and takes the guess work out of having a clean and powerful running 2t at any temp or altitude. We were able to use our stock cable, and the thumbscrew option for the top cap is a worthy option making fine tuning even easier than before. The bikes run and sound great with the Lectrons installed. The fun factor of a responsive and crisp running 2-stroke is pretty hard to beat while the frustration of a bogging, oil sputtering, plug fouling, rough running bike can flat out ruin a great day of riding. As a father of 2 (both kids racing) along with 4 bikes to keep maintained and prepped, it has been a huge relief to not deal with jetting for the massive temp and altitude variances here in CO. Once the initial set-up and tuning is done, I can rely on our Lectrons to be pretty spot-on in just about every situation we encounter. Overall, weve been very happy with the product and would absolutely recommend it to anyone looking for consistent reliable performance for their 2-stroke machines.

F
Frank D
Great Performance Upgrade!

Performance with a punch in a small package ..is the best way I can describe it!Lectron has done an amazing job with the development of this series carb.We ride the Supermini class hare scrambles and the occasional MX using the same bike...and the difference is clearly noticeable!!We get better response and upper band power as well as increased horsepower and fuel economy.Its a silver bullet for anybody whos fought the factory carbs and all the adjustments for changing conditions...the time saved from changing out and testing the jets is now spent prepping for our race which makes the events considerably more enjoyable. The Lectron carb is really just plug and playits that simple.Id like to just say thank you to all the folks at Lectron.. your product has made our machines scream and have reliability that we never had before.Complete game changer!!

C
Chris
Big Air Review

I recently purchased the Big Air for a 1983 CR480R. I have used and been happy with the Billetron in a 250 so decided to pull the trigger on one for the 480. The Big Air came set up just a tad rich from the bottom to midrange, but only by a 1/4 of a turn. The 480 is notoriously a hard starter, but to my surprise it started up very easily with the new Big Air carb. The carb is smooth from the crack of the throttle all the way through the top end. I would highly recommend this carb for the big bore two stroke enthusiast out there. Basically plug and play, and the smoothness of the powerband is a great trait on these big bores.

123