I have been staggered by the alterations possible by a programmable ECU when Ben gets on the rolling road with his k100, ignition point and mixture are altered in situ on the laptop with the engine pounding away. Back on the Vincent a lambda sensor plugged in the exhaust and the slots in the BTH body make some running changes possible
This is a very good technical thread, but doesn't really answer the question that's niggling me and probably a few more owners of standard Vincents. The Riders Handbook tells the average owner how many degrees before TDC at full advance was recommended. Disregarding worn ATDs and all the other variations that alter the fully retarded position, what is now (if different) the best setting for a standard bike for general riding using lead free petrol as supplied in the UK? References to shape of modern combustion chambers, high compression, twin sparks, fast burn, slow burn, racing, sprinting etc. are interesting, but most bikes are pretty standard. There appears to be some disagreement among all the technical talk as to how modern petrol behaves.
If it was possible for the factory in the `40s to provide a good compromise, surely with so much knowledge in the VOC someone can tell us how many degrees we should be using now?
Vince Farrell