Peeps, I'm considering replacing the old Weber system on my Cagiva Elefant with a Seeduino set up. The existing system is 30 years old and the fuel pump relay voltage is only just acceptable. Plus the corrosion of the steel cover screws in the housing indicates that repair will be difficult! Thus we come to the possible Speeduino set up. My first issue is that I will need to install a suitable trigger wheel. The current intention is to attach a trigger wheel to the existing cam wheel that is driven direct from the crankshaft. This has the advantage that I can replace the existing sensor which looks on the the face of the cam wheel. This gives me an effective outer diameter of 98mm. Using a 15mm radial width tooth a 36 tooth wheel would give a spacing of 8.5mm at the outer edge. Is this sufficient to trigger a sensor or should I be looking at a 24 tooth wheel. Thoughts and comments would be appreciated. There's a significant amount of machining required and I would like to do only once.
Yes, it does have a trigger set up off the cam, but it’s different to the later Ducati’s such as the ST2, in that there is only a single trigger ‘tooth’ on the cam wheel. To be honest was unaware of how the later Ducati’s achieved timing. The early Weber systems as on my Elefant uses a crankshaft sensor for RPM measurement and a cam wheel sensor for crankshaft / piston position.
Looking at your photo I assume that the ST2 timing wheel is driven from the end of the end of the cam shaft with a quill in the slot.
Attached is a photo of my original camshaft gear, I have acquired a cam wheel similar to what is on the ST2 to which I will add a supplementary toothed wheel which will locate in the slot.
Camwheel P3260083.JPG (818.52 KiB) Viewed 377 times
The ST2 Wheel I have only has the single 'chop' in the teeth, which will only give a single pulse. I was under the impression that the Speeduino needed a multiple tooth wheel. Also, the position of the existing cam sensor is set inboard from the gear teeth, again so it only gives one pulse for 720 degrees of crank rotation.
If your ST2 trigger wheel looks the same as the picture I posted before.
Then it wil work on speedduino.
ST2 sensor is reading sideways so it sees the 48-2 pattern.
You need to shim the sensor to get it close enough to the wheel.
Speeduino works on the 48-2 trigger wheel, have a setup running on the bench.
Hi, Hopefully below is a picture of the wheel acquired, which I believe is the same as in your picture, however the sensor on the original 900ie engine is centred on the single blade in my previous picture. Thus not sure if it will pick up the 48 - 2 teeth. One I think I need to try before getting to far along the machining route. Many thanks for the heads up as this may well save me faffing about.
IMG_20201104_174856788.jpg (3.71 MiB) Viewed 311 times