Kids Motocross: Ages, Classes, Bikes and First-Season Cost

A kid can race motocross from age 4. That is the minimum age for competition in the 2026 AMA Racing Rulebook, and youth classes run from there through age 17, stepping up from 50cc to 65cc, 85cc and Supermini. As of 2026 a new starter 50 is $1,899, and a first season of eight local races comes to roughly $3,700 on a Yamaha PW50 or $6,400 on a YZ65, before travel.

Age is only half of the rule. The AMA also says a youth rider must be “large enough and mature enough” to control the bike at all times, which includes stopping, starting, standing still, getting on and off, and putting a foot on the ground. The referee can disqualify a rider who cannot.

What are the youth motocross classes by age?

These are the AMA’s youth motocross classes for 2026. A local track picks from this list, and may add its own, so always read the flyer for the race you are entering.

AMA class	Age	Engine	Wheel and size limits
Micro Jr. Limited	4-6	0-51cc	10 in max wheels, 24 in max seat height, single-speed automatic
Micro Sr. Limited	7-8	0-51cc	12 in max wheels, single-speed automatic
Micro Shaft Drive Limited	4-8	0-51cc two-stroke	10 in max wheels, 22 in max seat height
Micro Special Limited	4-8	0-51cc	Named models only, including the Yamaha PW50 and Honda CRF50
Mini-E Jr. and Sr. Limited	4-6 and 7-8	1 kWh and 1.5 kWh battery	12 in max wheels; 25 in and 28 in max seat height
65cc	7-9, 10-11 or 7-11	59-65cc two-stroke	12 in min wheels, 14 in max front
85cc	9-11, 12-13, 14-15	79-85cc two-stroke	19 in front and 16 in rear max (9-11: 17 in and 14 in)
Supermini	12-16	79-112cc two-stroke, 75-150cc four-stroke	19 in front and 16 in rear max
Schoolboy 1	12-17	86-125cc two-stroke, 75-150cc four-stroke	19 in front and 16 in rear minimum
Schoolboy 2	12-17	122-250cc two-stroke, 126-250cc four-stroke	53 in minimum wheelbase
Girls Junior	9-12	59-85cc two-stroke	17 in max front, 12 to 16 in rear
Girls Senior	12-16	79-112cc two-stroke, 75-150cc four-stroke	19 in front and 16 in rear max

A few rules around the table that matter to parents:

• Age is set on January 1. In AMA youth competition a rider’s age on January 1 is their age for the rest of the year. A rider can move up an age class early if they will reach it during the year, but cannot move back down.
• “Limited” means close to stock. Limited classes are for approved bikes with restricted modifications, and minicycles must race in the class they were built for. Supermini and Schoolboy are the exceptions.
• Help is allowed for the smallest riders. The referee may allow outside assistance for 0-51cc riders who fall or stall.
• Bigger bikes have their own age floors. The minimum age for AMA amateur classes is 12, a rider must be 14 to ride 201cc to 250cc and 16 for 251cc and up. What comes next is in 250F vs 450.

How are the Loretta Lynn’s classes different?

The MX Sports 2026 national classes, used for the AMA Amateur National at Loretta Lynn’s and its qualifiers, cut the ages a little differently:

MX Sports class	Age	Engine	Wheel limit
Micro-E	4-7	1 kWh battery	Not listed
Micro 1 Shaft Drive, Micro 2	4-6	0-51cc	Not listed
Micro 3	7-8	0-51cc	Not listed
65cc	7-9 and 10-11	59-65cc	Not listed
85cc	10-12	79-85cc	17 in front, 14 in rear max
Mini Sr. 1 and 2	12-14 and 13-15	79-85cc two-stroke	19 in front, 16 in rear max
Supermini 1 and 2	12-15 and 13-16	79-112cc two-stroke, 75-150cc four-stroke	19 in front, 16 in rear max
Girls	11-16	79-112cc two-stroke, 75-150cc four-stroke	19 in front, 16 in rear max
Schoolboy 1 B/C	12-17	86-125cc two-stroke, 75-150cc four-stroke	19 in front, 16 in rear minimum
125 Jr. B/C	12-17	122-125cc two-stroke	Not listed

The practical difference: an 85 rider can start at 9 under the AMA list but 10 at a Loretta Lynn’s qualifier, and MX Sports notes a Girls class rider must be 12 to ride a Supermini.

Which bike fits which age?

Buy the bike that fits the kid and the class today, not the one they will grow into. Seat height is the number to check first, because the AMA’s own test is whether the rider can stop and put a foot down.

Bike	Engine and gearbox	Seat height	Weight	MSRP
2027 Yamaha PW50	49cc two-stroke, automatic, shaft drive	18.7 in	90 lb wet	$1,899
2027 Honda CRF50F	49cc four-stroke, 3-speed, automatic clutch	21.6 in	111 lb curb (2026)	$1,899
2027 KTM 50 SX	49.9cc two-stroke, single speed	25.7 in	96 lb, no fuel	$5,099
2027 KTM 65 SX	64.9cc two-stroke, 6-speed	28.7 in	120 lb, no fuel	$5,899
2027 Yamaha YZ65	65cc two-stroke, 6-speed	29.7 in	134 lb wet	$4,499
2027 Yamaha YZ85	85cc two-stroke, 6-speed	33.1 in	161 lb wet	$5,199
2027 KTM 85 SX 17/14	84.9cc two-stroke, 6-speed	Not listed	150 lb, no fuel	$6,949

Notes on the table:

• KTM figures are converted. KTM lists 653 mm and 730 mm seat heights and 43.5, 54.3 and 68 kg without fuel. Yamaha’s wet weight and Honda’s curb weight include a full tank, so compare within a brand.
• MSRP excludes destination. Yamaha adds $215 to the PW50 and $320 to the YZ65 and YZ85. KTM adds $425 freight. Honda’s price is from its 2027 announcement, and the CRF50F weight is from the 2026 spec sheet.
• The 85 comes in two wheel sizes. KTM sells the 85 SX 19/16 at $7,249. Under AMA rules the big wheels are too large for the 9-11 class and legal from 12-13 up.

2027 Yamaha PW5018.7 in

2027 Honda CRF50F21.6 in

2027 KTM 50 SX25.7 in

2027 KTM 65 SX28.7 in

2027 Yamaha YZ6529.7 in

2027 Yamaha YZ8533.1 in

View as table

Item	Value
2027 Yamaha PW50	18.7 in
2027 Honda CRF50F	21.6 in
2027 KTM 50 SX (653 mm; adjustable from 634 to 682 mm)	25.7 in
2027 KTM 65 SX (730 mm; adjustable from 715 to 760 mm)	28.7 in
2027 Yamaha YZ65	29.7 in
2027 Yamaha YZ85	33.1 in

Source: Yamaha, Honda and KTM, checked October 2026

How those line up with the classes:

• PW50 and CRF50F: learn to ride, then race the stock classes. Both have a throttle limiter a parent can adjust, and neither needs a clutch hand. The AMA names both in its Micro Special Limited class for ages 4 to 8. The PW50’s 18.7 inch seat is the lowest here by almost three inches.
• KTM 50 SX: a race bike. It is built for the 0-51cc classes and costs $3,200 more than a PW50. Its standard seat height converts to more than the 24 inch limit in the AMA’s 4-6 Micro Jr. class, so read that rule and measure before entering a small rider on one.
• 65s: the first clutch and gearbox. Both the YZ65 and 65 SX are six-speeds. The YZ65’s 14 inch front and 12 inch rear tires sit inside the 65cc wheel rule.
• 85s: 9 or 10 and up. The YZ85 runs a 17 inch front and 14 inch rear, the small-wheel size the youngest 85 class requires.

Every race bike from 50 to 85 here is a two-stroke, which means premix fuel and regular top ends. See 2-stroke vs 4-stroke and the maintenance schedule by hours. Kids outgrow bikes fast, so plenty of families buy used. Take the used dirt bike buying checklist with you.

What gear does a kid need to race?

The AMA’s motocross apparel rule applies to every rider, whatever their age. Mandatory, as of 2026:

• Full-face helmet for practice and racing, with a label showing a listed standard such as DOT FMVSS 218, Snell M2020 or M2025, or ECE 22-05 or 22-06. It must fit properly, be in good condition and be fastened. Nothing, cameras included, may be attached to it.
• Shatterproof goggles or face shield.
• Boots at least 8 inches high, or built for leg and foot protection.
• Long-sleeve jersey and protective pants of leather or other durable material.
• Chest and back protection. The rule says it should cover the sternum, front and back ribs, and the spine from T1 to T12.

The rulebook also recommends gloves, a neck brace and knee braces.

List prices for a youth set on the makers’ own sites, October 2026:

Item	List price
Helmet: Bell Moto-9 Youth Mips, DOT and ECE	$279.95
Boots: Alpinestars Youth Tech 3S, sizes 2-8	$199.95
Jersey: Fox Youth 180	$39.95
Pants: Fox Youth 180	$109.95
Chest guard: Fox Youth Raceframe Roost	$99.95
Total	$729.75

The helmet, jersey, pants and chest guard were all discounted when I checked, so the real bill can be lower. Smaller feet get the Kids Tech 3S at $189.95. Goggles, gloves and knee guards are not in the total because I did not price them. Before you buy any chest protector, hold it against the AMA wording above and ask at sign-up if you are unsure it qualifies.

One thing a parent should hear from us and not find later: the American Academy of Pediatrics recommends that children under 16 not operate ATVs at all. That page is about ATVs, not dirt bikes, but the reasoning it gives is about skill, reflexes and strength. Racing is a risk a family chooses with open eyes. Talk to your child’s doctor if you have questions about whether it suits your kid.

What does a first season cost?

Two examples, both new bikes at 2026 prices and eight one-day local races in one class. I used the Washougal Classic 7 series fees because they are published in full: $50 per class, $20 per person at the gate on Sunday (non-riders aged 5 and under are free) and $10 a day to rent a transponder.

Line item	50cc: Yamaha PW50	65cc: Yamaha YZ65
Bike, with destination	$2,114	$4,819
Gear, list price	$730	$730
AMA youth membership	$35	$35
Entry fees, 8 races	$400	$400
Gate, rider and one parent	$320	$320
Transponder rental	$80	$80
First season	$3,679	$6,384

The AMA youth membership is $35 a year for riders 11 or younger. A standard membership is $49, and the $119 family membership covers up to five people with no more than two adults, which is the better deal once a parent or a second kid races.

Fees vary a lot by track. High Point Raceway charges $55 to $60 per class and $20 to $30 at the gate. Chasing Loretta Lynn’s adds a $25 per class MX Sports fee at each Area Qualifier on top of the track’s entry.

Not in the table: the drive, tires, fuel and premix, top ends, crash parts and a second class. The adult numbers for all of those are in what it costs to race motocross, and travel is usually the biggest line.

How does a family get to a first race?

1. Ride first. The AMA’s test is control: stop, start, stand still and put a foot down. A kid who can do that for a full practice day is ready to try a gate.
2. Pick a local track and read its class list. Find the class that matches your kid’s age on January 1 and the bike you own.
3. Join the AMA if the race is AMA-sanctioned, or buy a day pass where the track sells one. Washougal’s is $30.
4. Bring proof of age. The AMA accepts a birth certificate, passport or state ID, and the referee can ask for it at any meet.
5. A parent signs and stays. A parent, legal guardian or authorized adult must sign the entry form below the rider’s signature and remain present the whole time the rider is taking part. Another adult needs a notarized authorization from the parents.
6. Pack the night before. Use the race day checklist, and read how to start racing dirt bikes for sign-up, practice and how a moto day runs.

Motocross is not the only way in. Off-road series run youth classes too. See racing disciplines explained and how to start racing WORCS, NGPC and District 37.