The big first start date 7 Nov 21
Well, it's been a couple of months since last posted. Reasonable progress made in which I installed the new wiring harness (
Motorworks) and ignition system (Dynatek). After refitting the gearbox, air filters, carbs and adjusting the clutch I rolled her off the workbench and took her outside. I fitted the tank off my track bike and connected up the fuel lines. I had already spun the starter with the top plugs out to circulate the oil. Plugs back in and went for the starter button.
I'm happy (no, more than that) to report that the engine fired first stab and settled to a good, fast, even idle. I was so stunned I forgot to take the choke off, and she slowed and stalled. I hit the starter again and off she went, so off came the choke and I held her on idle briefly before 'letting go' and observing her warm up for the first time. The tickover was set fast and she sounded happy, smooth and even. I checked the timing on the strobe and she's spot on for what I had set statically and for full advance. She's also charging well (thanks to new rotor and uprated stator). To say I was chuffed would be an understatement!
She's now back on the workbench awaiting front brakes (under-tank M/C) and bodywork and other small things (indicators, cables etc) - see picture. This will probably take me to the Spring.
Twin-spark timing. I did lots of research and I came across an article about it done by Tom Cutter of Rubberchicken Racing in USA. He seemed to know his stuff. There were also plenty of threads here and there on ADVrider, BMW MOA etc. Despite updating his article from 1981 in 2003, Tom Cutter still has a disclaimer that some of the information is erroneous (but doesn't say which). Anyway, in it he recommends setting twin-spark static timing to 3 degrees After TDC (ATDC) - yes, after - for 1000cc engines. So I initially set the timing up for that. It didn't seem right so the other day I contacted Jim Cray to double-check. I was so glad I did, as Jim said if I had set it to ATDC and tried to start it I'd have probably ruined the engine! As he re-built it for me, I set the timing to standard, minus about 1 or 2 degrees. The advance needed to go to the top of the 'Z' marker bracket (I have a light flywheel) when revving up. It goes to show that you can't believe all the internet material that is available - best talk to the experts!