First, some background: The ’76 – ’80 KZ750 Twins came with a points-based ignition system as standard equipment. And when the line was started up again for the ’82 model year, it featured an electronic ignition.
So if you have a later model, this post is not for you. 😉
However, if you have one of the earlier ’76 – ’80 models, you might just be wondering if there are after-market or alternative electronic options to replace those old high-maintenance points… so let’s jump in to that…
In a nutshell, you have these options (some more realistic than others):
- Newtronic (updated 20160814) – My first electronic ignition I bought for my first 750 was from Newtronic Systems Ltd. Since I bought it in 2004-ish (and it has been flawless since then), they have since come under NEW OWNERSHIP by Autocar. Interestingly, they appear to be available again in 2016 (or perhaps before, I’m not sure). Here is a link to the page for the Ignition (currently 132 GBP), part # CKT-KAW3, and the PDF instructions. I’m not endorsing them necessarily, but wow, come to think of it, mine has lasted about for about 12 years of regular use at the time of this writing.
- Dyna S (half of one, at least) – I have read a bit about fitting half of a standard Dyna S ignition to a points plate, and I try to summarize the essentials here…. As fellow KTOF member Martijn put it, “A Dyna S has no black box. The unit on the base plate is all!! only a current wire from the system and a wire to the coil, that’s all. It’s trigger is a magnet in the plastic rotor simply placed on the ATU. That’s why the Dyna S is so simple and that’s why if you buy one for a four cylinder you get two units and you only have to buy an extra trigger. On ebay for approx $ 120 (=dyna S for the Z650) rotor will be $20. You use the advancer of the stock ignition. You only take of the piece of metal with the lobe on it. (which opens your contact breaker. Replace this with the Dyna rotor which also slides over the bolt. Bolt it and replace ignition plate. One wire to the + other to the coil et voila.
You only change ignition plate and rotor so you still have the advance characteristics of your own. ” KTOF member Northwin added this, “…bought a Dyna S 2-2 (1695 SEK) and installed it in my 750 B2. The timing do not fit, you must move the electric unit counterclockwise on the ignition plate in order to get correct timing. The rotor placed on the existing timing advancer do not fit very well,there’s too much play.”
- Other-model stock electronic ignition – Fellow KTOF member Steell installed a KZ440 electronic ignition on his first 79 750 twin, and a 82-83 KZ750 twin electronic ignition on his current 79 750 twin. Forum member Ibsen had expressed concern over using the 440 ignition, in that “the 440 are advancing the timing to approx 40 degrees at 2800 degrees while the 750 have a different timing curve, and doesn’t advance the ignition that much”. However, forum member Shoe48 had a 82 440 ignition in his 79 B4, and mentioned that the “extra advance seems to help as I have no problems.”
- Boyer-Bransden (no longer available from vendor) – This is an official response from Boyer: “Unfortunately, we discontinued manufacture of a system for the Z750 twins a number of years ago. This system consisted of a MK3 ignition unit, stator plate with single pickup coil and a rotor with a single magnet, crankshaft triggered. The unit switched a standard dual output coil.
If you have a practical approach to mechanics and electrics we could supply you the parts from other kits, for example by using the stator & rotor for a Kawasaki Z400-Z650 and the ignition unit from a British Triumph Twin.
One of the stator pickup coils would need to be removed and a link wire
soldered in its place, also one of the magnets removed from the rotor. The kit of parts required would cost approximately £90.00 plus ignition coil/s if required.
If the bike has serviceable contact breakers, you could easily fit our
Negative Earth Inductive Discharge (I.D.) unit. This unit improves the spark and the bikes performance whilst greatly reducing wear at the contacts. You would need one unit for each set of breakers. The part number is: KIT00069 @ £29.93”
- Custom/Hybrid Solution – Like KTOF member Lou’s “GM HEI Ignitor for Points”, which uses the original points as a trigger for an igniter.
I hope that helps! And let me know if you find another way….