Motocross

Yamaha YZ450F 2027

Motocross, 450cc 4T, US version

Verified

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

From the owner’s manual: engine oil capacity 0.94 L (0.99 US qt), p. 2-2; coolant 1.03 L (1.09 US qt), p. 2-2; front tire 80/100-21 51M, p. 2-5; rear tire 120/80-19 63M, p. 2-5. Checked 16 Oct 2026.

No CPSC recall found for the 2027 Yamaha YZ450F, checked 2026-10-15. Recalls

Spec card PDF

Gearing

5 of 5 filled

Stock front sprocket: 13T; Verified, read off the manual page: Manual p. 2-4 · checked 2026-10-16 source [1]
Stock rear sprocket: 51T; Verified, read off the manual page: Manual p. 2-4 · checked 2026-10-16 source [1]
Chain pitch: 520; Verified, read off the manual page: Manual p. 2-7 · checked 2026-10-16 source [1]
Stock chain links: 114; Verified, read off the manual page: Manual p. 2-7 · checked 2026-10-16 source [1]
Stock final drive ratio: 3.923 : 1; Verified, read off the manual page: Manual p. 2-4 · checked 2026-10-16 source [1]

Wheels and tires

4 of 4 filled

Front rim: 21x1.6; Verified, read off the manual page: Manual p. 2-5 · checked 2026-10-16 source [1]
Rear rim: 19x2.15; Verified, read off the manual page: Manual p. 2-5 · checked 2026-10-16 source [1]
Front tire: 80/100-21 51M; Verified, read off the manual page: Manual p. 2-5 · checked 2026-10-16 source [1]
Rear tire: 120/80-19 63M; Verified, read off the manual page: Manual p. 2-5 · checked 2026-10-16 source [1]

Suspension

5 of 7 filled

Fork: Telescopic fork; Verified, read off the manual page: Manual p. 2-6 · checked 2026-10-16 source [1]
Fork travel: 310 mm (12.2 in); Verified, read off the manual page: Manual p. 2-6 · checked 2026-10-16 source [1]
Shock travel: 295 mm (11.6 in); Verified, read off the manual page: Manual p. 2-6 · checked 2026-10-16 source [1]
Stock fork spring rate: 5 N/mm; Verified, read off the manual page: Manual p. 10-3 · checked 2026-10-16 source [1]
Stock shock spring rate: 56 N/mm; Verified, read off the manual page: Manual p. 10-4 · checked 2026-10-16 source [1]
Static sag, bike only: Not yet verified
Race sag, rider on: Not yet verified

Fluids and capacities

5 of 5 filled

Engine oil spec: SAE 10W-40 (or 10W-50, 15W-40, 20W-40, 20W-50), API SG or higher, JASO MA; Verified, read off the manual page: Manual p. 2-2 · checked 2026-10-16 source [1]
Engine oil capacity (oil change): 0.94 L (0.99 US qt); Verified, read off the manual page: Manual p. 2-2 · checked 2026-10-16 source [1]
Engine oil capacity, with filter change: 0.96 L (1.01 US qt); Verified, read off the manual page: Manual p. 2-2 · checked 2026-10-16 source [1]
Coolant capacity: 1.03 L (1.09 US qt); Verified, read off the manual page: Manual p. 2-2 · checked 2026-10-16 source [1]
Fuel capacity: 6.2 L (1.6 US gal); Verified, read off the manual page: Manual p. 2-2 · checked 2026-10-16 source [1]

Service specs

6 of 6 filled

Fork oil: Yamaha Suspension Oil S1; Quantity (left) 501.0 cm³ (16.94 US oz, 17.67 Imp.oz); Quantity (right) 501.0 cm³ (16.94 US oz, 17.67 Imp.oz); Verified, read off the manual page: Manual p. 2-6 · checked 2026-10-16 source [1]
Brake fluid: DOT 4; Verified, read off the manual page: Manual p. 2-5 · checked 2026-10-16 source [1]
Coolant type: High quality ethylene glycol antifreeze containing anti-corrosion for aluminum engine; Verified, read off the manual page: Manual p. 3-23 · checked 2026-10-16 source [1]
Fuel octane: Octane number (RON) 95; Verified, read off the manual page: Manual p. 2-2 · checked 2026-10-16 source [1]
Idle speed: 1900–2100 r/min; Verified, read off the manual page: Manual p. 2-4 · checked 2026-10-16 source [1]
Valve clearance: Intake 0.10–0.17 mm (0.0039–0.0067 in); Exhaust 0.15–0.22 mm (0.0059–0.0087 in), cold; Verified, read off the manual page: Manual pp. 2-2, 2-3 · checked 2026-10-16 source [1]

Maintenance

3 of 3 filled

Tire pressure (off-road): 100 kPa (15 psi) front and rear; Verified, read off the manual page: Manual p. 2-5 · checked 2026-10-16 source [1]
Chain slack: 50.0-60.0 mm (1.97-2.36 in), on a maintenance stand; Verified, read off the manual page: Manual p. 2-7 · checked 2026-10-16 source [1]
Spark plug and gap: NGK LMAR8G, gap 0.7-0.8 mm; Verified, read off the manual page: Manual p. 2-2 · checked 2026-10-16 source [1]

Dimensions

3 of 3 filled

Seat height: 965 mm (38.0 in); Verified, read off the manual page: Manual p. 2-1 · checked 2026-10-16 source [1]
Wheelbase: 1475 mm (58.1 in); Verified, read off the manual page: Manual p. 2-1 · checked 2026-10-16 source [1]
Weight (curb weight): 109 kg (242 lb); Verified, read off the manual page: Manual p. 2-1 · checked 2026-10-16 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. 2-7Stock chain links 114 Owner's manual p. 2-7520 chains at MotoSport 520 master links at MotoSport
Sprockets: Stock front sprocket 13T Owner's manual p. 2-4Stock rear sprocket 51T Owner's manual p. 2-413T front sprockets at MotoSport 51T rear sprockets at MotoSport
Tires: Front tire 80/100-21 51M Owner's manual p. 2-5Rear tire 120/80-19 63M Owner's manual p. 2-5Front tires 80/100-21 at MotoSport Tubes 80/100-21 at MotoSport Rear tires 120/80-19 at MotoSport Tubes 120/80-19 at MotoSport
Engine oil: Engine oil spec SAE 10W-40 (or 10W-50, 15W-40, 20W-40, 20W-50), API SG or higher, JASO MA Owner's manual p. 2-2Engine oil capacity (oil change) 940 ml (31.8 fl oz) Owner's manual p. 2-2Engine oil at MotoSport
Coolant: Coolant capacity 1030 ml (34.8 fl oz) Owner's manual p. 2-2Coolant at MotoSport
Suspension springs: Stock fork spring rate 5 N/mm Owner's manual p. 10-3Stock shock spring rate 56 N/mm Owner's manual p. 10-4Suspension 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 120/80-19

Chain, stock pitch 520, stock length 114 links

Chains are sold by link count; this bike's stock chain is 520 pitch, 114 links.

Engine oil, stock viscosity 10W-40

Matched on viscosity only. The manual prints: SAE 10W-40 (or 10W-50, 15W-40, 20W-40, 20W-50), API SG or higher, JASO MA. 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.

Use this bike

Tools for this bike

Compare with

All 27 comparisons for this bike

Other model years

All 7 model years, 2021 to 2027, side by side

Service schedule

94 rows from the owner's manual schedule, pp. 3-2 to 3-5, counted in races, at these intervals:

After break-in
Every race
Every third race
Every fifth race
As required

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

29 of 31 fields read off a manual page.

Not yet verified (2): static sag, race sag.

See coverage for every bike

Sources

1
Yamaha 2027 YZ450F Owner's Service Manual (YZ450FV, USA), LIT-11626-40-37, D03-2819U-11; owner-supplied copy from Yamaha's Owner's Manual Librarypp. 2-1, 2-2, 2-2, 2-3, 2-4, 2-5, 2-6, 2-7, 3-23, 10-3, 10-4Manual page, verified. Covers stock front sprocket, stock rear sprocket, chain pitch, stock chain links, stock final drive ratio, front rim, rear rim, front tire, rear tire, fork, fork travel, shock travel, stock fork spring rate, stock shock spring rate, engine oil spec, engine oil capacity (oil change), coolant capacity, fuel capacity, tire pressure (off-road), chain slack, spark plug and gap, seat height, wheelbase, weight (curb weight), engine oil figure, as labelled, engine oil capacity, with filter change, 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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