Here are my notes:
You want master assembly 43015-1495 / 1353
This one works well for 81 kz550D1.
Throw is about 13mm, a little shorter than the KZ550D rear master.
Bolt spacing is 49mm, same as the D1 master.
Requires two 11.0mm long, 15.8mm OD, 8.1mm ID, mounting spacers to match the KZ550D1 rear master.
Requires M8x1.25 - 40mm long bolts for mounting.
Reservoir hose must be cut down to fit frame.
Requires a 106mm long, push rod with at least 15mm of M8 x 1.25 threads on each end.
Requires an M8 x 1.25 threaded rod coupler to connect push rod to master rod.
Rebuild kit K&L 32-4228
These are the bikes to choose from.
EX250-F2(Ninja 250R)(1988)
EX250-F3(Ninja 250R)(1989)
EX250-F4(Ninja 250R)(1990)
EX250-F6(Ninja 250R)(1992)
EX250-F7(Ninja 250R)(1993)
EX250-F8(Ninja 250R)(1994)
EX250-F9(Ninja 250R)(1995)
EX250-F10(Ninja 250R)(1996)
EX250-F11(Ninja 250R)(1997)
EX250-F12(Ninja 250R)(1998)
EX250-F13(Ninja 250R)(1999)
EX250-F14(Ninja 250R)(2000)
EX250-F15(Ninja 250R)(2001)
EX250-F16(Ninja 250R)(2002)
EX250-F17(Ninja 250R)(2003)
EX250-F18(Ninja 250R)(2004)
EX250-F19(Ninja 250R)(2005)
EX250F6F(Ninja 250R)(2006)
EX250F7F(Ninja 250R)(2007)