1981 KZ550D1 (Gpz) ignition notes by Lou Dudzik 8/14/05, updated 12/3/18: Coils: Kawasaki part numbers: 21121-1035 and 1036. TEC, Toyo Denso Co. Ltd. Primary DC resistance: Factory specs are 1.8 to 2.8 ohms. Nominal 2.3 ohms. Actual measurements tend to be 2.4 to 2.7 ohms. Primary inductance: 6.33 mH (Measured) Module: Kawasaki part number: 2119-1040 Fuji built Fuji label part number: 2119-1020 Pickups: Kawasaki part number 59026-1009 TEC, Toyo Denso Co. Ltd. DC resistance: 450 to 460 ohms. inductance: 350 mH Magnets: Both magnets are identical. If the polarity is in question, it can be checked. Hold the magnets together. Stripe-to-stripe repel. Blank-to-stripe attracts. That means both white stripes are the same pole. When mounted to the plate, the same pole on both magnets faces the timing plate. If one magnet is flipped, the magnetism will be very weak. If both are flipped, the signal will get inverted. The stripe does not necessarily tell which face is north, so is not the indicator to use to determine which way to install the magnets. The south pole must face away from the engine. The north pole faces toward the engine. A known magnet can be used to determine the polarity of the magnets. Or an electromagnet can be used. Another test is to put the assembly together such that both stripes face the engine or both stripes face away from the engine. If they are correct, the voltage on the black wire (using blue as ground) will be positive as an iron object approaches the pickup. The voltage will be negative if the magnets are backwards, so they should be flipped. Same for the yellow wire. It should be positive (using red as ground) as an iron object approaches the pickup. Negative when it moves away. When everything is correct, the 1-4 pickup coil produces a positive signal on the black wire (blue as ground) as the rotor tip approaches the pickup. It produces a negative signal as the rotor tip moves away from the pickup. When everything is correct, the 2-3 pickup coil produces a positive signal on the yellow wire (red as ground) as the rotor tip approaches the pickup. It produces a negative signal as the rotor tip moves away from the pickup. The rear pickup is the black/blue pickup. Black is (+), blue is (-). This pickup controls the right hand side ignition coil (on Kz550, 400-4, 500, 650, and 750-4), which is the 1-4 coil and is fired by a black wire. The front pickup is the yellow/red pickup. Yellow is (+), red is (-). This pickup controls the left hand side ignition coil (on Kz550, 400-4, 500, 650, and 750-4), which is the 2-3 coil and is fired by a green wire. Performance: Dwell at idle: 100 deg (crankshaft) Dwell increases to 120 deg (crankshaft) as rpm increases With about a 1mm gap from rotor tip to pickup, the peak POSITIVE (not peak to peak) output spike is about: .2v at 120 rpm (2Hz) .3v at 180 rpm (3Hz) 7v at 6000 rpm (47Hz) (Battery powered start is somewhere around 300 rpm (5hz).) These measuments represent positive signal peak relative to ground (ie, when the negative pickup wire is grounded), NOT peak to peak. The negative spike, as measured on the positive pickup wire (with negative pickup wire grounded), has about 50% of the positive peak's amplitude. These measurements are accurate even when hooked up to an ignitor. Any ignitor will have to have very high input impedance to prevent signal delay, thus the pickup's output voltage, under load, will remain very similar to an un-loaded pickup's output voltage. Rotor: It is an iron slug with an increasing-radius ramp up to a pronounced point with a decreasing-radius ramp after the point. The increasing ramp takes about 126 deg and the decreasing ramp takes 234 deg. This iron slug is just pressed on. Flipping it over (while keeping the point at the same location) can theoretically nearly double the dwell to 234 deg, but the signal becomes less clear and thus more unstable and false triggers result. The long-ramp has dips and bumps that cause the false signals. Also, for some reason, the dwell, in this condition, only ranges from 80 deg to a maximum of 180 ~ 220 deg instead of the theoretical 234 deg regardless of the how high the rpm is. Perhaps 10,000 rpm does not produce enough amplitude with such a gradual ramp. A diagram of the pickup's output voltage is visible in the file called "KzRelucSignalApprox_copy.GIF". Due to the nature of inductive pickups, there is a small delay that increases with rpm. This delay ranges from 0 deg to about 3 deg (crankshaft) at 10,000 rpm. The effect will be seen as about a 2 to 3 degree retard on the spark at high rpm. It's not very noticeable til around 8000 or 9000 rpm. This delay appears with the stock ignitor as well as other ignitor modules that have been constructed and substituted. ----------------------The following ignitor-usage data was compiled by "luvmykaw" on KZrider.com.---------------------------------------- The ignitor for a 1982 H3 750 LTD, part number 21119-1040 is a direct swap with: KZ550-A2-81 Standard KZ550-A3-82 Standard KZ550-A4-83 Standard KZ550-C1-80 LTD KZ550-C2-81 LTD KZ550-C3-82 LTD KZ550-C4-83 LTD KZ550-D1-81 Gpz KZ550-F1-83 SPECTRE KZ550-M1-83 SHAFT KZ650-H1-81 CSR KZ650-H2-82 CSR KZ750-E1-80 KZ750-E2-81 KZ750-H1-80 LTD KZ750-H2-81 LTD KZ750-E3-82 KZ750-H3-82 LTD KZ1000-G1-80 Igniter part number 21119-1050 will only cross between these bikes: KZ650-H3-83 CSR KZ750-H4-83 KZ750-L3-83 KZ750-R1-82 GPZ