- Mon Jan 06, 2025 10:48 am
#70403
Good morning. I have a 650cc parallel twin four stroke engine that seems a good candidate for conversion using Speeduino. I'm really only interested in ignition conversion, at least for now. Here's where my thoughts are.
It's a simple 360 degree four stroke OHC motor running a single twin output coil in wasted spark mode. Standard ignition is camshaft mounted points with mechanical auto advance (removed in the picture below). I don't believe I will be able to generate a usable crankshaft signal so I would be using a toothed wheel and hall sensor at the camshaft. I can accommodate a toothed wheel upto maybe 60mm, which sounds a bit small to me and I have no idea about a suitably small hall sensor.
Sounds fairly straight forward to me having read the technical documentation about Speeduino. If anything, Speeduino is way over what is required. But I can't find a system any simpler than the NO2C Speeduino. Hence why I'm here.
Two pictures below. One of the crankshaft mounted alternator, I think getting a clean signal from here isn't really viable. And the other picture is the camshaft end. The camshaft is hollow, has a ~8mm hole right through the centre and I can easily mount a toothed wheel or gear wheel on there. Hall sensor I have no idea about but I don't think it's impossible providing I can find a suitable compact device. Using existing ignition coil, I would have to identify a suitable coil driver which presently I haven't looked at. I think that's about it for now. If I understand this correctly, I only need a signal from the camshaft toothed wheel to give me a workable but simple ignition system. Thanks.


It's a simple 360 degree four stroke OHC motor running a single twin output coil in wasted spark mode. Standard ignition is camshaft mounted points with mechanical auto advance (removed in the picture below). I don't believe I will be able to generate a usable crankshaft signal so I would be using a toothed wheel and hall sensor at the camshaft. I can accommodate a toothed wheel upto maybe 60mm, which sounds a bit small to me and I have no idea about a suitably small hall sensor.
Sounds fairly straight forward to me having read the technical documentation about Speeduino. If anything, Speeduino is way over what is required. But I can't find a system any simpler than the NO2C Speeduino. Hence why I'm here.
Two pictures below. One of the crankshaft mounted alternator, I think getting a clean signal from here isn't really viable. And the other picture is the camshaft end. The camshaft is hollow, has a ~8mm hole right through the centre and I can easily mount a toothed wheel or gear wheel on there. Hall sensor I have no idea about but I don't think it's impossible providing I can find a suitable compact device. Using existing ignition coil, I would have to identify a suitable coil driver which presently I haven't looked at. I think that's about it for now. If I understand this correctly, I only need a signal from the camshaft toothed wheel to give me a workable but simple ignition system. Thanks.

