The Garage

Enduro

Stock-size parts in stock at MotoSport

Kawasaki KX450X 2026

Enduro, 449cc 4T, US version

Partly verified

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

From the owner’s manual: engine oil capacity 0.9 L (1.0 US qt), p. 52; coolant 1.1 L (1.2 US qt), p. 55; front tire 80/100-21 51M, p. 13; rear tire 120/90-18 65M, p. 13. Checked 16 Oct 2026.

Model year on file: 2026 only. Other years are added as their manuals are read.

No CPSC recall found for the 2026 Kawasaki KX450X, checked 2026-10-15. Recalls

Kawasaki KX450X 2026

Workshop card from motoxsports.com/bikes/kawasaki-kx450x/ · each figure as the maker’s document prints it, with its source number; ≈ marks a figure we converted. Torque values are not published: use the manual.

Gearing

3 of 5 filled

Stock front sprocket
13T
Verified, read off the manual page: Manual p. 12 · checked 2026-10-11 source [1]
Stock rear sprocket
50T
Verified, read off the manual page: Manual p. 12 · checked 2026-10-11 source [1]
Chain pitch
Not yet verified
Stock chain links
Not yet verified
Stock final drive ratio
3.846 : 1
Verified, read off the manual page: Manual p. 12 · checked 2026-10-11 source [1]

Wheels and tires

4 of 4 filled

Front rim
21 x 1.60
Verified, read off the manual page: Manual p. 1-3 · checked 2026-10-11 source [3]
Rear rim
18 x 2.15
Verified, read off the manual page: Manual p. 1-3 · checked 2026-10-11 source [3]
Front tire
80/100-21 51M
Verified, read off the manual page: Manual p. 13 · checked 2026-10-11 source [1]
Rear tire
120/90-18 65M
Verified, read off the manual page: Manual p. 13 · checked 2026-10-11 source [1]

Suspension

3 of 7 filled

Fork
49mm Showa inverted telescopic coil-spring fork with 21-way adjustable compression and 22-way adjustable rebound damping
Research level: Spec sheet (research) · checked 2026-10-11 source [2]
Fork travel
305 mm (12.0 in.)
Verified, read off the manual page: Manual p. 1-3 · checked 2026-10-11 source [3]
Shock travel
307 mm (12.1 in.)
Verified, read off the manual page: Manual p. 1-3 · checked 2026-10-11 source [3]
Stock fork spring rate
Not yet verified
Stock shock spring rate
Not yet verified
Static sag, bike only
Not yet verified
Race sag, rider on
Not yet verified

Fluids and capacities

4 of 4 filled

Engine oil spec
SAE 10W-40; API SG, SH, SJ, SL or SM with JASO MA, MA1 or MA2
Verified, read off the manual page: Manual p. 12 · checked 2026-10-11 source [1]
Engine oil capacity (when filter is removed)
0.9 L (1.0 US qt)
Verified, read off the manual page: Manual p. 52 · checked 2026-10-11 source [1]
Coolant capacity
1.1 L (1.2 US qt)
Verified, read off the manual page: Manual p. 55 · checked 2026-10-11 source [1]
Fuel capacity
6.2 L (1.6 US gal)
Verified, read off the manual page: Manual p. 12 · checked 2026-10-11 source [1]

Service specs

6 of 6 filled

Fork oil
Type Kawasaki Fork Oil A15-00; Amount: Cylinder Unit 248 mL (8.38 US oz.); Outer Tube KX450N 315 mL (10.7 US oz.)
Verified, read off the manual page: Manual p. 13 · checked 2026-10-16 source [1]
Brake fluid
Front Brake Fluid : DOT4 or DOT5.1; Rear Brake Fluid : DOT4
Verified, read off the manual page: Manual p. 120 · checked 2026-10-16 source [1]
Coolant type
Permanent type of antifreeze (ethylene glycol plus corrosion and rust inhibitor chemicals for aluminum engines and radiators); Water and Antifreeze Mixing Ratio 1:1 (water:antifreeze)
Verified, read off the manual page: Manual p. 55 · checked 2026-10-16 source [1]
Fuel octane
Antiknock Index 90
Verified, read off the manual page: Manual p. 26 · checked 2026-10-16 source [1]
Idle speed
2 250 – 2 350 r/min (rpm)
Verified, read off the manual page: Manual p. 74 · checked 2026-10-16 source [1]
Valve clearance
Intake 0.08 – 0.12 mm (0.0031 – 0.0047 in.); Exhaust 0.14 – 0.18 mm (0.0055 – 0.0071 in.)
Verified, read off the manual page: Manual p. 102 · checked 2026-10-16 source [1]

Maintenance

3 of 3 filled

Tire pressure (off-road)
100 – 125 kPa (1.0 – 1.2 kgf/cm², 14 – 18 psi)
Verified, read off the manual page: Manual p. 171 · checked 2026-10-11 source [1]
Chain slack
48 – 54 mm (1.9 – 2.1 in.)
Verified, read off the manual page: Manual p. 108 · checked 2026-10-11 source [1]
Spark plug and gap
NGK CPR8EB-9
Verified, read off the manual page: Manual p. 12 · checked 2026-10-11 source [1]

Dimensions

3 of 3 filled

Seat height
37.4 in (≈ 950 mm, converted by MotoXSports)
Research level: Spec sheet (research) · converted from 37.4 in · checked 2026-10-11 source [2]
Wheelbase
1 480 mm (58.27 in.)
Verified, read off the manual page: Manual p. 1-2 · checked 2026-10-11 source [3]
Weight (curb Mass)
113.4 kg (250.0 lb)
Verified, read off the manual page: Manual p. 1-2 · checked 2026-10-11 source [3]
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.

Sprockets
Stock front sprocket 13T Owner's manual p. 12Stock rear sprocket 50T Owner's manual p. 1213T front sprockets at MotoSport50T rear sprockets at MotoSport
Tires
Front tire 80/100-21 51M Owner's manual p. 13Rear tire 120/90-18 65M Owner's manual p. 13Front tires 80/100-21 at MotoSportTubes 80/100-21 at MotoSportRear tires 120/90-18 at MotoSport
Engine oil
Engine oil spec SAE 10W-40; API SG, SH, SJ, SL or SM with JASO MA, MA1 or MA2 Owner's manual p. 12Engine oil capacity (when filter is removed) 900 ml (30.4 fl oz) Owner's manual p. 52Engine oil at MotoSport
Coolant
Coolant capacity 1100 ml (37.2 fl oz) Owner's manual p. 55Coolant at MotoSport

In stock at MotoSport

Prices from MotoSport’s catalog of Oct 14, 2026; check today’s price before you buy.

Front tire, stock size 80/100-21

Rear tire, stock size 120/90-18

Engine oil, stock viscosity 10W-40

Matched on viscosity only. The manual prints: SAE 10W-40; API SG, SH, SJ, SL or SM with JASO MA, MA1 or MA2. Check the label for the rest.

Spark plug, stock NGK CPR8EB-9

Prices and stock from MotoSport's product catalog on Oct 14, 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.

4 part specs not yet verified; see data coverage.

Tools for this bike

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Service schedule

60 rows from the owner's manual schedule, pp. 44-48, counted in races, at these intervals:

  • After each race
  • Every 3 races
  • Every 6 races
  • Every 12 races
  • 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.

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
Setup B — what you are thinking about
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

23 of 31 fields read off a manual page.

Not yet verified (6): chain pitch, chain links, fork spring rate, shock spring rate, static sag, race sag.

From a spec sheet, awaiting a manual page (2): fork, seat height.

See coverage for every bike

Sources

  1. 1
    Kawasaki Owner's Manual KX450 / KX450X / KX450SR (KX450M/N/P), item 99814-0121, © 2025 Kawasaki Motors, Ltd., Feb. 14, 2025 (1); e-book on Kawasaki's manual portal (pws.ktivs.net); no model year printed, Kawasaki's own owner's manual portal lists it for model year 2026 (owner decision 2026-10-12)pp. 12, 13, 26, 52, 55, 74, 102, 108, 120, 171Manual page, verified. Covers front tire, rear tire, fuel capacity, stock final drive ratio, stock front sprocket, stock rear sprocket, engine oil spec, engine oil capacity (when filter is removed), coolant capacity, spark plug and gap, chain slack, tire pressure (off-road), engine oil figure, as labelled, fork oil, brake fluid, coolant type, fuel octane, idle speed, valve clearance; checked 2026-10-16.
  2. 2
    2026 KX™450X model page, MODEL SPECS (kawasaki.com, en-us)Manufacturer web or spec sheet, research level. Covers fork, seat height; checked 2026-10-11.
  3. 3
    Kawasaki Specifications 99888-0048-01 (KX450M/N/P), the specifications supplement the owner's manual links to on its p. 14; no model year printed, Kawasaki's own owner's manual portal lists it for model year 2026 (owner decision 2026-10-12)pp. 1-2, 1-3Manual page, verified. Covers fork travel, shock travel, wheelbase, weight (curb Mass), front rim, rear rim, weight, as labelled; 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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