Ignition timing with Thorspark electronic ignition

[The-Pope]

Morning to you all, last night I fitted my Thorspark and set it for initial start up by making sure the magnet on the Thorspark rotor is in the right place on the electronic pick up. It started first kick and ran ok ish but I still need to time it with a strobe. Question is this. It’s a 57 model 30 and the Manual says 39 degrees before TDC. Is this still what people use with modern fuels?

Secondly. Rather than loosen and move the rotor in the shaft to perfect the timing can I just use the threaded adjuster on the mags Manual Advance /retard cable (so long as I still have enough to retard for starting). On a mg ignition this wouldn’t work as you wouldn’t get the strongest spark at full advance but with E ignition that wouldn’t happen?

I have also read a couple of threads say to set it with the A/R lever very slightly retarded to enable a touch if extra advance if needed out on the road. Is this commonly done?

Just a thought but I don’t know enough to foresee any drawbacks, what do think?
Thanks in advance (no pun )

[Groily]

I think you could, yes, to your second point. At least to find the sweetest spot right now, and maybe leave long term because twins of reasonable compression ratio don't need massive retard to avoid kickback on starting. Proviso is that if there's slack on the plunger in the notch it engages with, there's a potential risk of flutter, which might be reduced if the plunger were held right down against whatever the limit stop is on the Thorspark (if there is one). (That certainly applies with camrings, anyway.)

Ref the exact amount of advance, I don't have a 600 so haven't played with them. I'd say 'per book should be fine, but maybe a degree of two less' - better advice may be forthcoming. In any case, you can tweak away happily and see what suits best out on the road, which might depend a little bit on what jungle juice you put in.

[The-Pope]

Thank you. That makes sense I hadn’t thought of it being off the stop might have a detrimental effect. I’ll experiment and see. Cheers.