Rain today - and most of next week apparently - so thought I'd give the GF vee twin a bit of a check over now it's done a few miles.
Wanted to remove the distributor to check the bevel gears, as I wasn't sure they were getting enough oil (transpires they are) but doing so would lose the ign timing, and that's a bit of a PITA to check. Usual stick down plug 'ole doesn't work, as the plug is recessed quite a bit in the fins making visibility difficult.
I wasn't busy, so decided to set the engine at firing point on front cylinder by virtue of points just opening, and then fabricate a rod against which the piston would rest at that point. I know such devices are available commercially, but they're really only fit for side-valvers and other motors with a vertical plug. Furthermore, alloy heads have the long thread, so even a stick down the hole would unlikely be vertical, making any reading thereon meaningless. Naturally this tool, once adjusted for this engine, would have to be re-adjusted for another - making the exercise pointless. So it'll stay with this bike for future use, meaning I just screw it in the plug hole and bring the piston up to it instead of having to strip the primary side to attach a timing disc.
As an aside, I use a CTZ14-S 12v battery -it's actually smaller than the 6v it replaces despite having over 200A CCA. I fit it on end (being ADM that's fine) and actually have to pack it on top to reach the battery strap. No need to bend or modify the battery tray at all.