Japanese UJM guides
Suzuki GS750 / GS1000 / KZ1000 / KZ750 / Z1 / XS1100 - one era, six DOHC and stroker-bore fours.
The Japanese UJM (Universal Japanese Motorcycle) inline-four era landed in the late 1970s and closed out the early 1980s with six DOHC and stroker-bore fours across three vendors. Suzuki’s PEI magneto-driven thyristor ignition runs across the GS750 (1977-1983); the GS1000 (1978-1983) carries the cross-era PEI to CDI ignition pivot at 1981. Kawasaki’s Z1 / Z1A / Z1R (1973-1980) and KZ1000 (1977-1980) carry CDI trigger pickup ignition across the run with the Z1R-derivative four-pipe cylinder head torque step; the 1976-1983 KZ750 (738cc DOHC) carries the same oil-fed cam-chain tensioner body through the 1979 CDI pivot year on the KZ750H LTD. Yamaha’s XS1100 (1978-1981) carries the Yamaha TCI transistor controlled ignition on the stroker-bore shaft-drive chassis.
Spec comparison
Japanese UJM at a glance
Year-specific deltas live inside each per-guide page - use this table to match your machine to the right Suzuki / Kawasaki / Yamaha DOHC or stroker-bore inline-four guide.
| Model | |||||
|---|---|---|---|---|---|
| Suzuki T500/GT hubWater-cooled two-stroke era | 500 cc | 70 mm | 64 mm | 6.5:1 | Contact-breaker pointsMikuni VM28SC 28 mm slideSuzuki water-cooled two-stroke hub -- pre-DOHC family antecedent of the GS chassis; positive-earth, NOT 12 V negative-earth. |
| Yamaha XS6501970-1985 | 653 cc | 75 mm | 74 mm | 9.0:1 | Points (1970-79) -> TCI (1980-85)Mikuni BS32 (1970-79) -> BS34 (1980+) CVSOHC pushrod-twin cousin to the DOHC XS1100 -- three ignition eras (pre-77 stamped rocker, 1977+ shim-under-bucket, 1980+ TCI) and two washable gauze-mesh oil filters. |
| Kawasaki KZ7501976-1983 | 738 cc | 66 mm | 66 mm | 9.0:1 | Points (1976-78) -> CDI trigger (1979+ KZ750H/KZ750R)Mikuni BS34 34 mm slideOil-fed cam-chain tensioner 4-6 mm travel -- mid-displacement sibling to the Z1 / KZ1000 with the 1979 CDI pivot year. |
| Suzuki GS7501977-1983 | 748 cc | 65 mm | 56.4 mm | 8.7:1 | PEI (NO CDI on the GS750)Mikuni BS34 34 mm CVPEI throughout the 1977-1983 run -- never CDI; 1980 GS750E 4-pipe head is optical spec at the same 34 N.m torque window. |
| Kawasaki Z1 / Z1A / Z1R1973-1980 | 903 cc | 66 mm | 66 mm | 8.4:1 | CDI trigger pickupMikuni VM28SC 28 mm slideKawasaki DOHC stroker anteceding the KZ1000 -- the Z1R four-pipe head derivative is the 38 N.m four-pipe torque window precedent. |
| Suzuki GS10001978-1983 | 997 cc | 70 mm | 66 mm | 8.8:1 | PEI 1978-1980 / CDI 1981+Mikuni BS36-SW 36 mm CVCDI cross-era pivot at 1981 -- yellow/red wire replaces green/black PEI; 1980 GS1000E 4-pipe head steps 34 N.m to 38 N.m. |
| Kawasaki KZ10001977-1980 | 1015 cc | 70 mm | 66 mm | 8.5:1 | CDI trigger pickupMikuni VM34SC 34 mm slideKawasaki Z1R-derivative 4-pipe head torque step at 38 N.m three-stage -- analogous to the GS1000E 4-pipe head step. |
| Yamaha XS11001978-1981 | 1101 cc | 71.5 mm | 68.6 mm | 8.5:1 | TCI (Transistor Controlled Ignition)Mikuni BS38 38 mm CVYamaha TCI is magneto-driven transistor ignition; shaft-drive final-drive (distinct from the GS / KZ chain final-drive family). |
Precision tolerance bands, per-bore-service limits, and the model-specific tool list sit inside each per-guide page. This hub indexes the family - the per-guide content carries the spec card.