Model identification and model changes


Where to find the serial numbers. (click the image to enlarge)


(K)Z400/400 Specs

1974 D1

1975 S1 D2

1976 D3 S2

1977 D4 S3 A1

1978 B1 C1

1979 B2 G1 H1

1980 A1 B1 D1

1980 B3 G2 C1

1981 A2 B2 D2

1981 B4 G3 H3

1981 C2

1982 H4 R1 H1

1982 A3 D4 G1

1983 R2 T1 H2

1983 A4 D5

1984 D6



KZ400/440 model identification

By Ian Powell

Frame numbers for the 1975 KZ400S
Since the 1975 KZ400 S was produced at two different plants in two different countries, the frame numbers will have two different serials.
Bikes prodused at the Kawasaki plant in Lincoln, Nebraska, USA, will have frame numbers from : K4S-50001.
Bikes produced at the Kawasaki plant in Akashi, Japan will have frame numbers from: K4S-00021.
The engines used are all from the same serial, starting at : K4SE000023.

Frame numbers for the 1976 KZ400 D3

Bikes pruduced at the Lincoln Factory will have frame numbers from: K4-506001

Bikes produced at the Akashi factory will have frame numbers from: K4-044601

The engine numbers are from the same serial, starting at : K4E050601


Model id list


The first number are the engine number

398cc (K)Z400-B1 1978 K4E118001 K4-077801 Candy Persimmon Red

398cc (K)Z400-B2 1979 K4E139801 K4-099501 Candy Emerald Green

398cc (K)Z400-D4 1977 K4E095101 K4-065101 Candy Super Red

398cc (K)Z400D 1975 K4E013844 K4-013800 Candy Super Red

398cc (K)Z400D3 1976 K4E050601 K4-044601 Diamond Blue

398cc KH400-A5 1978 S3E042801 S3F-042801 Candy Persimmon Red

398cc KX400/KX400-A3 1975/1976 K5E903001 K5-903001 Lime Green

398cc KZ400-A1

398cc KZ400-H1 (LTD) 1979 K4E152831 KZ400H-000101 Ebony

398cc KZ400-H1 (LTD) 1980

398cc KZ400-S2 1976 K4SE010701 K4S-04601 Diamond Red

398cc KZ400C1 1978 K4SE033701 K4S-24701 Luminous Copper

398cc KZ400C2 1979 Information Required Information Required Information Required

398cc KZ400D 1974 K4E00001 K4-00001 Halibut Red

398cc KZ400D 1975 K4E00000 K4-00000 Candytone Super Red

398cc KZ400G1 (Custom) 1979 K4E152289 / K4G000001 K4-099501 Ebony

398cc KZ400S 1975 K4SE00001 K4S-00001 Candytone Super Red

398cc KZ400S3 1977 K4SE027101 K4S-18101 Candy Orient Blue

398cc Z400-B3 1980 K4E169501 K4-115001 Firecracker Red

398cc Z400-B4 1981 K4E169501 K4-116801 Metallic Red

398cc Z400-G2 (Custom) 1980 K4E169501 K4-115001 Ebony

398cc Z400-G3 (Custom) 1981 K4E175234 K4-11801 Luminous Spring Green

398cc Z400-H3 (LTD) 1981 K4E175234 KZ400H-0.17202 Ebony

398cc Z400-H4 1982 K4E183218 KZ400H-024510 Ebony

398cc Z400-J1 1980 KZ400EE011501 KZ400J-000001 Grandprix Silver

398cc Z400-J2 1981 KZ400EE028001 KZ400J-003101 Moondust Silver

398cc Z400-J2 1981 KZ400EG000701 KZ400J-003101 Moondust Silver

398cc Z400-J3 1982 KZ400EE084001 KZ400J-008701 Luminous Gun Blue

398cc Z400-J3 1982 KZ400EG001601 KZ400J-008701 Luminous Gun Blue

398cc Z400-M1 1983 West Germany KZ400EG003201 KZ400M-016501 Firecracker Red

398cc Z400-R1 1982 K4E183201 KZ400R-000001 Metallic Ultramarine Blue

398cc Z400-R2 1983 K4E184501 KZ400R-000401 Galaxy Silver

398cc Z400-T1 1983 K4E184501 KZ400T-000001 Luminous Midnight Red

398cc ZR400-A1 1981 KZ400EE072001 ZR400A-000001 Polar White

398cc ZR400-B1 1984 ZX400AE000001 ZR400B-000001 Polar White

398cc ZR400-B1 1984 ZX400AG000001 ZR400B-000001 Polar White



(JUN 80) Z440C1, Introduced, 6-Spd. E/start, Alloy wheels, chain drive

(FEB 81) Z440A2, Custom version, stepped seat, teardrop tank High rise handlebars alloy wheels megaphone style exhausts finished in Red or Ebony.

(MAY 81) Z440C2 (KZ440C-003301) Replaces the Z440C1 with new graphics and finishes, Green or Red. A twin cradle frame rear passenger grab rail and Black finish rear suspension units

(FEB 82) Z440C2 Discontinued

(FEB 82) Z440H1 (KZ440H-000001) Introduced, similar to the Z440C but with larger wheels and finished in Blue or Black or Silver

(FEB 82) Z440D4 (KZ440D-004401) Introduced, the Belt Drive version of the Z440A2 and finished in Red or Blue

(MAY 82) Z440A2 Discontinued

(FEB 83) Z440H2 (KZ440H-001701) Replaces the Z440H1 with new finishes of Red or Silver

(FEB 93) Z440D5 (KZ440D-007501) New decals and finished in Red or Silver the front disc brake is held to the hub by 7 allen screws rather than 4 bolts

(AUG 83) Z440H2 Discontinued

(NOV 83) Z440D6 (KZ440D-012101) Replaces the Z440D5 finished in new Ebony colour

(MAR 85) Z440D6 Discontinued

Supplement list


There were basically four models of Z400 twin the KZ400, the Z400D, Z400B and Z400G. The first two shared the early engine design which wasn't Kawasaki's best. Among other problems it used to strip the teeth off the balancer shaft drive on the crank which effectively totalled the engine. The motor was redesigned for the Z400B from engine number K4E139801 and was much improved. The Z400B can be easily identified from the earlier bikes as it has a tailpiece; the Z400G is the same as a B but has cast wheels. Not many parts are interchangeable between the early and late motors. The Z440 was a direct descendent of the B/G series and lots of parts will fit. The barrels and pistons are different, the cylinder head are the same, carbs are different.
Barrels/Pistons Z440 Barrels and Pistons can be put on a Z400 B, C, G and H bottom end and Visa Versa as both have the same stroke and lubrication system.

Big End Shells Check Size but all are compatible as long as same colure code

Cables all the same if same handlebar height used

Carbs. These cannot be swooped from model to model without a lot of work it is far better to correct the set you have than to change( For new Diaphragms call NRP who will fit new ones to your existing slides at a fraction of the cost of new ones)

Clutch Cover Late Z400/440s use same Clutch Covers. The early Z400 one can be made to fit if you shave off the edge next to the Generator and open up gear change hole and cover fixing holes

Crank Cases Late Z400/440s use same Cases

Crank/Cam a Z440 Crank and Cam Can be put into the early Z400 and visa versa they must be changed as a pair along with the chain as the Z400 uses a single link chain and the Z440 uses a hyvo chain

Cylinder Head Early Z400 cannot be exchanged but later Z400 and Z440 use the same head

Fork Seal Z400/Z440 1978/1984 All Z400s and 440s along with the Z250 use the same seals

Forks can be exchanged as all are same diameter but as model progressed it went from drum to disc with a change in the bottom fork leg. And the bottom fork leg also changed between the different disc brake models, so you will need to either swap stanchions or fit correct wheel assy. Also the length of the fork tubes will vary between the different models.

Frame. You can fit any Z400/Z440 engine into any frame all are exchangeable but there are differences in the frames but with work all can be used.

Generator Late Z400/440s use same Generator Stator and Cover

Headstock (triple tree). All Z400/Z440s use the same headstock

Kick Start. The none Kick Start Models can have one fitted by fitting an early Case and Kick start Splines and Spring though the kick-start itself changed so check if you have the right one (Early kick start swivel at top Late swivel from bottom)

Oil Filters GPX250/KZ400/Z400/Z440/Z440 LTD/Z750 Twin there are also Honda models that will fit I will add these soon.

Points Plate/Ignition Cam Z250/Z400/Z440/Z750 All use the same points plate and Ignition Cam

Wheel Bearings Take No from Bearing and go to your local bearing stock holders as they will be just as good as the ones you will get from a bike dealership and they will be cheaper

Wheels All Standard Wheels can cross over from modal to modal Z400/Z440 and if you want to lower the back end a 16" wheel from an LTD will fit except if it’s a belt drive one you will have to convert back by fitting a 45t Sprocket


More model history