05-04-2021, 08:47 PM
I also find that varying the Chummy's timing (with a BLIC) makes a considerable difference to the performance. However, with the Cup (which has a BTH) it seems to have hardly any effect. The Chummy has the longer lever, the Cup has the shorter one. I assume the different lengths of levers were for different magnetos, but I have never seen anywhere which lever goes with which magneto. I would like to fit a longer lever to the Cup to see if that makes any difference, but I haven't got one, so one day I intend to fabricate an extension and braze it on to the shorter lever.