FJRiders.com

Road Runner wrote: ↑Mon Jun 17, 2024 9:30 pm Does it run good with old coils? If so, there's the problem. If not, then need to dig further. Then ohm check charge coils, trigger coils, Ignition coils.

Thank you for replying RR. I haven't tried. It's truly a PITA to swap coils on that bike. That's why I went to the bench. I'd also have to re-install the ballast resistor meaning changing the wiring again.

Soon my 'coil tester' will arrive so until then I've doing KrZy8 relay link maintenance and tires. Fortunately, the old KZ isn't a commute bike anymore.

raYzerman wrote: ↑Tue Jun 18, 2024 8:37 am You mention the KZ has igniters... I don't know anything about igniters, but had them on my old Magna, and bought spare set. Any spares to play with? These days, aftermarket replacements might be available.
And perhaps put your old coils to the test setup you had, see if they sparkie well, then perhaps the bike's system is the issue?

From what I've learned, and I'm no subject matter expert, but ignition systems typically break the circuit, as in open the switch, on coil negative. This 'switch' can be points (mechanical) or an ignitor (electronic).

An ignition is basically Darlington power transistors which can handle the relative high current involved in the primary coil. 13 volts with 3.5 ohm coil is approx 3.7 amps, which is why the Darlington configuration is used.

From Wikipedia-

In electronics, a multi-transistor configuration called the Darlington configuration (commonly called as a Darlington pair) is a circuit consisting of two bipolar transistors with the emitter of one transistor connected to the base of the other, such that the current amplified by the first transistor is amplified further by the second one.[1] The collectors of both transistors are connected together. This configuration has a much higher current gain than each transistor taken separately. It acts like and is often packaged as a single transistor. It was invented in 1953 by Sidney Darlington.

The QDB-3A arrived - here's a short video



https://candybuttorg.ipage.com/cba/comm ... mment-1237 for pics

D

to keep the thread intact, will keep adding as time goes on..

Did more bench testing using the super-dooper-party-sparker machine.

Tested
* FJR coils, Martek aftermarket coils
* Resistor vs non-Resistor plugs
* Reversed primary polarity

Which of the 3 do you think provided the hottest spark?

In the video I stated the FJR plug caps have an internal 5k resistor. .Now I'm not confident they do?

Don, the FJR plug caps have a 10k resistor..........

raYzerman wrote: ↑Tue Jun 25, 2024 8:17 pm Don, the FJR plug caps have a 10k resistor..........

Ahh, Thanks Ray. Got it confused with KZ1300 caps.

My o-scope arrived yesterday. Gonna play with it in a bit..