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[Wheaters]

A simple “computerised” ignition system such as a TCI unit has a pre-programmed advance curve, installed on non-volatile memory. It measures the time between engine rotation signal inputs and fires the coil (by earthing the primary winding) just like a points based system. By design it must work slightly “in arrears“ with regard to engine rpm. However, bearing in mind that at a 600 rpm idle it receives 10 inputs/second and at 3000 rpm it receives 50/sec, it’s obviously not an issue.

[Beezabryan]

https://accessories.hitchcocksmotorcycl ... a&_xt=.pdf

[Wheaters]

https://accessories.hitchcocksmotorcycl ... a&_xt=.pdf

Unfortunately that method of checking and adjusting the timing can’t be used unless the bike has a distributor fitted. The TCI equipped bikes have the generator stator and the trigger sensor fixed onto the inside face of the primary chain case cover so if you remove it the bike can’t be started.

[Cranky]

Actually you can strobe the UCE but as I have written in the post EFI no more you remove the clutch casing and fabricate a TDC as you have to do on the timing sides of the crank case. Yes a bit oily when it running but not that bad.

This is my point I know for an actual mechanical fact that my engine fires at 10 degrees before TD because the tab on the flywheel passes at that point, static or strobe proves that.

So where does 32 degrees come from. It cant bring the spark into the future is my point.

[Wheaters]

It’s computerised. It will fire the coil on a time interval base. Once it knows the rpm from the TDC signal it can fire in advance of the next engine revolution by switching at a shorter interval then resetting the datum. All it does is earth the primary winding of the coil and being electronic it will be a very clean switch off. How the advance curve is arranged between 9 and 32? I have no idea; it may be linear, or it might go in steps, or just be arranged to jump in one go at a preset rpm. I doubt it’s the latter on my 350 because it runs very smoothly and the pickup, such as when blipping the throttle, really is instant, especially so for a single.