Gas Dirt Bikes for Kids, Teens & Adults

Shop 40cc to 250cc gas dirt bikes engineered for kids, teens, and adult trail riders. From automatic 49cc and 50cc kids gas motorcycles with speed limiters to 110cc, 125cc, 150cc, and 250cc 4-stroke motocross bikes, every MotoTec dirt bike ships free with a Factory Warranty.

Gas Dirt Bikes Buyer's Guide: 40cc–50cc Kids Motorcycles to 250cc Adult Trail Bikes

Selecting the right gas dirt bike starts with matching rider inseam, weight, and clutch experience to engine displacement. As an authorized MotoTec dealer, our gas dirt bikes span beginner speed-governed youth bikes up to full-size 4-stroke trail and motocross machines—all backed by free insured U.S. shipping and a factory parts warranty.

  • 40cc–52cc Kids Gas Dirt Bikes (Ages 6–12, 22"–24" Seat Height): First-time riders thrive on automatic centrifugal-clutch models. The MotoTec Demon 40cc 4-Stroke runs on straight unleaded gas without oil mixing, while 2-stroke favorites like the Alien 50cc, Thunder 50cc, Pioneer 49cc, and Warrior 52cc deliver punchy trail acceleration with adjustable throttle limiters and dual disc brakes.
  • 60cc–110cc Youth & Teen 4-Stroke Pit Bikes (Ages 10–15, 24"–29" Seat Height): Step up to 4-stroke reliability with the automatic Hooligan 72cc or the 4-speed semi-automatic (clutchless shift) MotoTec X1 110cc and electric-start MotoTec X2 110cc.
  • 125cc, 150cc & 250cc Manual 4-Stroke Trail & Motocross Bikes (Teens 14+ & Adults): Experienced riders seeking full manual clutch control choose the MotoTec X3 125cc (30" seat), MotoTec X4 150cc (32" seat, electric + kick start), or full-size MotoTec X5 250cc 4-Stroke (36" seat, 5-speed transmission, 21"/18" wheels, up to 60 MPH).

Need help measuring your rider's inseam? Read our Dirt Bike Sizing Guide for Kids, Teens & Adults, compare silent lithium models in Electric Dirt Bikes, and gear up with DOT-certified Motocross Helmets.

40cc to 250cc Gas Dirt Bike Specification Comparison

Model Tier Engine & Transmission Top Speed Seat Height Max Rider Weight Recommended Rider
Demon 40cc / Alien 50cc / Thunder 50cc 40cc 4-Stroke or 49–52cc 2-Stroke (Automatic) 18–25 MPH (Governed) 22" – 24" 130–165 lbs Kids Ages 6–12
MotoTec X1 110cc & X2 110cc 110cc 4-Stroke OHV (4-Speed Semi-Auto) Up to 38–42 MPH 28" – 29" 185–200 lbs Youth & Teens (10–15)
MotoTec X3 125cc & X4 150cc 125cc / 150cc 4-Stroke (4/5-Speed Manual Clutch) 45–52 MPH 30" – 32" 210–220 lbs Teens 14+ & Adults
MotoTec X5 250cc 4-Stroke 250cc 4-Stroke Electric/Kick Start (5-Speed Manual) Up to 60 MPH 36" (21"/18" Wheels) 240 lbs Full-Size Adult Riders

49cc & 50cc Kids Gas Dirt Bikes: 2-Stroke Starter Motorcycles

Looking for a beginner-friendly 50cc dirt bike or 49cc dirt bike? Our 2-stroke kids gas dirt bike lineup—headlined by the MotoTec Thunder 50cc Kids Gas Dirt Bike ($409), MotoTec Alien 50cc ($409), and MotoTec Pioneer 49cc 2-Stroke ($359)—uses a fully automatic centrifugal clutch with zero gear shifting required. Parents can dial the handlebar throttle limiter screw down to 7–10 MPH for first-time learners or open it up to 22–25 MPH as confidence grows.

Gas Dirt Bikes by Rider Age: 7, 10, 12, 13, 14 & 15 Year Old Sizing Guide

Matching seat height and engine displacement to your child's inseam is the #1 key to safe trail riding:

Frequently Asked Questions

What size kids gas dirt bike is best for ages 6 to 12?

For kids ages 6 to 10 (18"–23" inseam), a 40cc 4-stroke (MotoTec Demon 40cc) or 49cc–50cc 2-stroke kids gas motorcycle (Alien 50cc, Thunder 50cc, or Pioneer 49cc) with a 22"–24" seat height, automatic clutch, and throttle governor is ideal. Riders ages 10 to 13 ready for more trail clearance typically step up to the 72cc Hooligan or 110cc X1/X2.

Should I choose a 2-stroke or 4-stroke kids gas motorcycle?

4-stroke gas dirt bikes (like the Demon 40cc, Hooligan 72cc, and X1–X5 110cc–250cc series) run on straight unleaded gasoline with smooth, predictable torque and quieter exhaust notes. 2-stroke 49cc–52cc youth dirt bikes run on a 25:1 gas-and-oil mix, weigh less for easy pickup, and offer snappy acceleration at a lower entry price.

Do 110cc, 125cc, and 250cc gas dirt bikes have automatic or manual clutches?

Our 40cc–72cc youth models are fully automatic (twist-and-go). The MotoTec X1 and X2 110cc models feature a 4-speed semi-automatic transmission (foot shifting without a hand clutch lever). The MotoTec X3 125cc, X4 150cc, and X5 250cc feature full manual hand clutches with 4-speed or 5-speed foot transmissions.