Fancy jig!!! I could put that to good use! I do the timing with the head on and a dial gauge on the inlet valve. I've been told thats the only way to do it. But there are many ways to skin a cat. I like your idea a lot better. My way is a pita!
On the Norton I'm running a 24/42 primary and a 21/42 final. Thats with a 100/90 19" rear wheel. On the sidecar I'm running 26/42 primary and 21/ 47 final with a 100/90 18" wheel. I have a 28t. sprocket for the sidecar engine on order through work. It was supposed to be here a week ago but disappeared in transit. Another is on the way but it doesn't look like it will make it before Bonneville. I have an old 19t. Weslake sprocket lined up as a donor (for the splines) but even if it arrives I don't think I'll have the time (see beach trip for the better half) to machine it. I think if I lean it out enough it can run 125+ at Bonneville. You know the old saying "Run rich. Run all season". I'm guilty of that. With Cosworth pistons $200+ I can't afford too many. 2005 El Mirage season was 5 runs, 3 pistons, a rod and a crankshaft. It was beans on toast for a good while after that season!
I wanted ask how you are going to start the wee beastie? I used to kick mine but as time went on I got to the point where I couldn't. I used a small engine to spin the back wheel and it worked pretty good. For the sidecar I made an adaptor on the engine sprocket and use a Dodge truck geared starter. That one I am in love with! So much so I did the same for the Norton.
Heres a couple of shots of the starter set up. Its dead easy to make and works a treat.
Heres the starter in action. May El Mirage. Making sure it starts. Nothing worse than to get to the line and find it won't start!
Don't cry because its over. Smile because it happened.