16-02-2018, 10:26 PM
Hi.
The three pole types are used to give a certain amount of engine advance. Ideally you want the engine to start with the spark at just about TDC or marginally after TDC so you don't get kick back on the pull cord.
Once started you need to advance the ignition and at full revs even more advance, if you don't advance the ignition the engine can overheat.
I opened up a Honda one some years ago and it was very simple, the coil a couple of caps, diode and perhaps a transistor, it may have been a dual diode as it got damaged with the hammer on the dismantling process. I think the later solid state ones use hall IC's for timing and the firing of the coil and also use a simple capacitor discharge circuit.
I'd be inclined to test this on substitution.
The three pole types are used to give a certain amount of engine advance. Ideally you want the engine to start with the spark at just about TDC or marginally after TDC so you don't get kick back on the pull cord.
Once started you need to advance the ignition and at full revs even more advance, if you don't advance the ignition the engine can overheat.
I opened up a Honda one some years ago and it was very simple, the coil a couple of caps, diode and perhaps a transistor, it may have been a dual diode as it got damaged with the hammer on the dismantling process. I think the later solid state ones use hall IC's for timing and the firing of the coil and also use a simple capacitor discharge circuit.
I'd be inclined to test this on substitution.
