Motocross

KTM 250 SX-F 2025

Motocross, 250cc 4T, US version

Verified

Illustration: a KTM motocross bike, not this exact model.

From the owner’s manual: engine oil capacity 1.0 l (1.1 qt.), p. 147; coolant 0.95 l (1 qt.), p. 147; front tire 80/100-21 51M TT, p. 149; rear tire 110/90-19 62M TT, p. 149. Checked 16 Oct 2026.

No CPSC recall found for the 2025 KTM 250 SX-F, checked 2026-10-15. Recalls

Spec card PDF

Gearing

4 of 5 filled

Stock front sprocket: 14T; Verified, read off the manual page: Manual p. 148 · checked 2026-09-23 source [1]
Stock rear sprocket: 51T; Verified, read off the manual page: Manual p. 148 · checked 2026-09-23 source [1]
Chain pitch: 520; Calculated, not printed: The trade name of the printed size 5/8 x 1/4" · Manual p. 148 · checked 2026-09-23 source [1]
Stock chain links: Not yet verified
Stock final drive ratio: 3.64 : 1; Calculated, not printed: Calculated from the stock sprockets, printed on manual p. 148

Wheels and tires

2 of 4 filled

Front rim: Not yet verified
Rear rim: Not yet verified
Front tire: 80/100-21 51M TT; Verified, read off the manual page: Manual p. 149 · checked 2026-09-23 source [1]
Rear tire: 110/90-19 62M TT; Verified, read off the manual page: Manual p. 149 · checked 2026-09-23 source [1]

Suspension

6 of 7 filled

Fork: WP XACT AER (air fork); Verified, read off the manual page: Manual p. 147 · checked 2026-09-23 source [1]
Fork travel: 310 mm (12.2 in); Verified, read off the manual page: Manual p. 147 · checked 2026-09-23 source [1]
Shock travel: 300 mm (11.81 in); Verified, read off the manual page: Manual p. 147 · checked 2026-09-23 source [1]
Stock fork spring rate: Not yet verified
Stock shock spring rate: 42 N/mm; Verified, read off the manual page: Manual p. 152 · checked 2026-09-23 source [1]
Static sag, bike only: 35 mm (1.38 in); Verified, read off the manual page: Manual p. 45 · checked 2026-09-24 source [1]
Race sag, rider on: 105 mm (4.13 in); Verified, read off the manual page: Manual p. 45 · checked 2026-09-24 source [1]

Fluids and capacities

4 of 4 filled

Engine oil spec: SAE 10W/50; Verified, read off the manual page: Manual p. 147 · checked 2026-09-23 source [1]
Engine oil capacity: 1.0 l (1.1 qt.); Verified, read off the manual page: Manual p. 147 · checked 2026-09-23 source [1]
Coolant capacity: 0.95 l (1 qt.); Verified, read off the manual page: Manual p. 147 · checked 2026-09-23 source [1]
Fuel capacity: 7.2 l (1.9 US gal); Verified, read off the manual page: Manual p. 147 · checked 2026-09-23 source [1]

Service specs

6 of 6 filled

Fork oil: Fork oil (SAE 4) (48601166S1): oil capacity external mechanism right 240 +10/−50 ml (8.11 +0.34/−1.69 fl. oz.); external mechanism left 240 +10/−50 ml (8.11 +0.34/−1.69 fl. oz.); right cartridge 380 ml (12.85 fl. oz.); Verified, read off the manual page: Manual p. 150 · checked 2026-10-16 source [1]
Brake fluid: DOT 4 / DOT 5.1; Verified, read off the manual page: Manual p. 94 · checked 2026-10-16 source [1]
Coolant type: High-grade, silicate-free coolant with corrosion inhibitor additive for aluminum motors; antifreeze protection to at least −25 °C (−13 °F); Verified, read off the manual page: Manual p. 157 · checked 2026-10-16 source [1]
Fuel octane: Super unleaded (ROZ 95); Verified, read off the manual page: Manual p. 147 · checked 2026-10-16 source [1]
Idle speed: 2,250 … 2,350 rpm; Verified, read off the manual page: Manual p. 144 · checked 2026-10-16 source [1]
Valve clearance: Intake at: 20 °C (68 °F) 0.08 … 0.15 mm (0.0031 … 0.0059 in); Exhaust at: 20 °C (68 °F) 0.12 … 0.19 mm (0.0047 … 0.0075 in); Verified, read off the manual page: Manual p. 144 · checked 2026-10-16 source [1]

Maintenance

3 of 3 filled

Tire pressure (off-road): 1.0 bar (15 psi) front and rear; Verified, read off the manual page: Manual p. 148 · checked 2026-09-26 source [1]
Chain slack: 58-61 mm (2.28-2.4 in); Verified, read off the manual page: Manual p. 82 · checked 2026-09-26 source [1]
Spark plug and gap: NGK LMAR9AI-10, gap 1.0 mm; Verified, read off the manual page: Manual p. 144 · checked 2026-09-26 source [1]

Dimensions

3 of 3 filled

Seat height: 958 mm (37.72 in); Verified, read off the manual page: Manual p. 148 · checked 2026-09-23 source [1]
Wheelbase: 1493 mm (≈ 58.8 in, converted by MotoXSports); Verified, read off the manual page: Manual p. 148 · checked 2026-09-23 source [1]
Weight (weight without fuel, approx.): 101 kg (223 lb.); Verified, read off the manual page: Manual p. 148 · checked 2026-09-23 source [1]

Solid marks are owner's-manual pages; hollow marks are manufacturer web or spec-sheet figures still waiting on a manual page. Last reviewed 2026-10-16. Rows marked not yet verified are blank on purpose.

Buying parts

The stock sizes and specs this bike left the factory with, each with its source. Take them to any shop.

Retailer links below are affiliate links: we may earn a commission, at no cost to you, and it never changes the specs. Affiliate disclosure.

Chain: Chain pitch 520 Owner's manual p. 148520 chains at MotoSport 520 master links at MotoSport
Sprockets: Stock front sprocket 14T Owner's manual p. 148Stock rear sprocket 51T Owner's manual p. 14814T front sprockets at MotoSport 51T rear sprockets at MotoSport
Tires: Front tire 80/100-21 51M TT Owner's manual p. 149Rear tire 110/90-19 62M TT Owner's manual p. 149Front tires 80/100-21 at MotoSport Tubes 80/100-21 at MotoSport Rear tires 110/90-19 at MotoSport Tubes 110/90-19 at MotoSport
Engine oil: Engine oil spec SAE 10W/50 Owner's manual p. 147Engine oil capacity 1000 ml (33.8 fl oz) Owner's manual p. 147Engine oil at MotoSport
Coolant: Coolant capacity 950 ml (32.1 fl oz) Owner's manual p. 147Coolant at MotoSport
Suspension springs: Stock shock spring rate 42 N/mm Owner's manual p. 152Suspension at MotoSport

In stock at MotoSport

Prices from MotoSport’s catalog of Oct 26, 2026; check today’s price before you buy.

Front tire, stock size 80/100-21

Rear tire, stock size 110/90-19

Engine oil, stock viscosity 10W-50

Matched on viscosity only. The manual prints: SAE 10W/50. Check the label for the rest.

Prices and stock from MotoSport's product catalog on Oct 26, 2026; they change, so check the price at MotoSport before you buy. Products are chosen by exact stock size, code or oil viscosity from the specs above, known brands first, then price. We have not tested them.

2 part specs not yet verified; see data coverage.

Use this bike

Tools for this bike

Compare with

Comparisons with other bikes use the newest model year on file: KTM 250 SX-F 2027.

Other model years

2025 vs 2027, side by side

Service schedule

57 rows from the owner's manual schedule, pp. 39-40, counted in hours, at these intervals:

After one operating hour
Every 15 operating hours
Every 45 operating hours
Every 90 operating hours
Every 24 months

Check what's due or track it in My Bike. Buying one used? The hours check lists what the schedule calls for by its meter reading.

Gearing calculator

Gearing for this bike

Put your current gearing in Setup A and the setup you are considering in Setup B. Everything updates as you type.

Start from a bike's stock gearing

Pick a bike to fill both setups with its stock sprockets.

Front sprockets 8–16 teeth, rear 34–60. Values outside that range are brought back to the nearest limit.

Setup A — what you run now

Front teeth

Rear teeth

Setup B — what you are thinking about

Front teeth

Rear teeth

Final drive ratio

— — : 1

—

Pull at the wheel—

Top speed—

Ratio change—

A —

B —

Taller · more speed Shorter · more pull

—

Changing the rear sprocket changes the chain length too. The chain length calculator works it out from the chain you have now, with where the axle ends up.

Ratios are exact. The chain figure is an estimate of roughly one link per two teeth of change — confirm against your manual before ordering.

What's missing

27 of 31 fields read off a manual page.

Not yet verified (4): chain links, front rim, rear rim, fork spring rate.

See coverage for every bike

Sources

1
KTM Owner's Manual 2025 250 SX-F / 250 XC-F / 250 SX-F Adamo Edition, Art. no. 3240043en (25.04.2024); owner-supplied copy, same document as the dealer-hosted PDFpp. 45, 82, 94, 144, 147, 148, 149, 150, 152, 157Manual page, verified. Covers stock front sprocket, stock rear sprocket, chain pitch, front tire, rear tire, fork, fork travel, shock travel, stock shock spring rate, engine oil spec, engine oil capacity, coolant capacity, fuel capacity, seat height, wheelbase, weight (weight without fuel, approx.), static sag, bike only, race sag, rider on, tire pressure (off-road), chain slack, spark plug and gap, engine oil figure, as labelled, weight, as labelled, fork oil, brake fluid, coolant type, fuel octane, idle speed, valve clearance; checked 2026-10-16.

Always confirm against the manual for your exact year before ordering parts or setting up suspension. Torque specs are deliberately not published here. How we verify a value.

Your manual prints something different? Report a value with the page it is on; every fix is listed in the corrections log.

My settings

Date / track
Sprockets run
Race sag / free sag
Fork air pressure or spring
Fork clickers (compression / rebound)
Shock clickers (low / high / rebound)
Tire pressures (front / rear)
Notes

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