What is the difference between a KX450 and a KX450F?

The KX450F is the pre 2019 bike with a kick start. The KX450 from 2019 onwards is all new with electric start.

How often should I change the oil in a KX450?

Every 5 to 10 hours depending on how hard it is ridden, with a filter every second change.

Is the KX450 a good used buy?

Yes. It is usually the cheapest of the Japanese 450s used and just as reliable.

The Yamaha turns sharper and holds its value better. The Kawasaki is more stable at speed and cheaper used.

Motocross · Four stroke

Kawasaki KX450

Kawasaki's 450 motocross bike since 2019, when the KX450F dropped the F and got electric start, a hydraulic clutch and a new engine. Fast, stable, and often the cheapest 450 in the class used. Sold in Australia from 2019 to 2026, 8 model years.

Add my KX450 to the Garage Shop parts for this bike

About the Kawasaki KX450

The KX450 is the bike Kawasaki built to take on the 450 class properly. The 2019 model was all new with electric start, a hydraulic clutch on the later years, a finger follower valve train and a chassis that is one of the most stable at speed. The 2024 bike was new again with a lighter frame, a slimmer feel and traction control through a phone app.

It suits a clubman or vet rider who wants a strong, stable 450 that costs less than the Yamaha or KTM used. It feels bigger than a YZ450F and it turns a little slower, but it is planted on fast tracks and very easy to ride. Parts are cheap and Kawasaki reliability is real.

What changed by year

2019 to 2020: All new: electric start, new engine and frame, spring fork, cable clutch. Strong and reliable.
2021 to 2023: Hydraulic clutch, revised engine and mapping, updated suspension. The most common used KX450.
2024 onwards: All new frame, engine and bodywork, phone tuning, traction control. The current bike.

Servicing a KX450

Oil every 5 to 10 hours depending on how hard it is ridden, filter every second change. It takes about a litre with a filter and a 10W 40 or 10W 50 full synthetic. Check the level with the sight glass after a warm up.

Air filter every ride. The finger follower valves hold their clearances well, but check them at the interval in the table. Plan on a piston around 40 to 50 hours for a race bike. Grease the linkage and swingarm after wet rides.

Engine hours between jobs: the schedule the Digital Garage tracks for this bike, based on the manual. Racers and hard riders go sooner, as above. Ride in sand or mud and halve the engine ones.

Job	Every
Air filter	3h
Engine oil & filter	15h
Gearbox oil	15h
Valve clearance	45h
Coolant flush	60h

Parts that fit a KX450

Motorex Formula 4 Stroke 10W40 4L
$99.95 · members $84.96
Motorex Cross Power 4T 10W60 - 1L
$47.50 · members $40.38
Motorex Gear Oil Sae 10W30 1L
$29.95 · members $25.46
Motorex Racing Pro Cross 10W40 4L
$154.95 · members $131.71
Motorex White Grease 100g
$31.95 · members $27.16
Motorex Hydraulic Fluid 75-200ml
$29.95 · members $25.46
Motorex 4 Stroke 20W50 4L
$79.95 · members $67.96
Motul Gearbox 1L 80W90 Moly
$42.90 · members $36.46
Motul Chain Lube Factory Line
$29.95 · members $25.46
Motul Parts Clean 840ml
$21.99 · members $18.69
Muc-Off Motorcycle Snow Foam 5L
$99.95 · members $84.96
Muc-Off Motorcycle Snow Foam 1L
$24.95 · members $21.21

Everything that fits a KX450 →

Buying a used Kawasaki KX450

Ask about hours, the last piston and the last valve check. Make sure it starts on the button hot and cold, and on the 2021 onwards bikes that the hydraulic clutch has a firm lever. Look at the airbox, the linkage bearings and the frame around the footpeg mounts. The KX450 is often the best value used 450 because it does not hold its price like a Yamaha or KTM; a well kept one is a bargain.

Recent sold prices are on the Marketplace page linked below.

Used Kawasaki KX450s for sale

2 listed on the MWMX Marketplace right now.

2022 Kawasaki KX450

$6,250ONO

72hVIC

2023 Kawasaki KX450

$6,200ONO

75hVIC

All Kawasaki KX450s for sale and recent sold prices →

Kawasaki KX450 known issues

Battery
A small lithium battery that does not like sitting flat. Keep it on a tender.
Clutch on 2019 to 2020
The cable clutch is a wear item under hard use. A notchy lever means a grooved basket.
Resale
Not a fault, but Kawasakis sell for less than the equivalent Yamaha or KTM. Good if you are buying, less good if you are selling.

Kawasaki KX450 questions

What is the difference between a KX450 and a KX450F?: The KX450F is the pre 2019 bike with a kick start. The KX450 from 2019 onwards is all new with electric start.
How often should I change the oil in a KX450?: Every 5 to 10 hours depending on how hard it is ridden, with a filter every second change.
Is the KX450 a good used buy?: Yes. It is usually the cheapest of the Japanese 450s used and just as reliable.
KX450 or YZ450F?: The Yamaha turns sharper and holds its value better. The Kawasaki is more stable at speed and cheaper used.