A bit of an update . . .
I looked at my neighbour's 3GL Matchless - he has a single magnet in his rotor and different instructions
Amazon delivered a nice, good quality, 'Silva' compass and I did some checking.
I tested the Matchless:- The North-pointing end of the compass points to the outer edge of the magnet.
I tested mine:- Both magnets have the same orientation with the North compass pointer pointing at them. This makes sense if the rotor is for a twin - both sparks will be identical.
I have ignored the instructions and removed one magnet; the bike has been running.
The exhaust is still very loud. I put this down to the increase in compression after I machined the barrel top face and fitted a 7.5:1 piston. I will remove the silencer and see if there is anything in there . . . .
. If not, its a call to Armours
The carburation isn't good. I swapped the 200 main jet for a 180 and the exhaust isn't showing black smoke any more, I have even had it ticking over but it won't pick-up cleanly from idle. I need to experiment with the air screw, needle position and throttle slide cutaway.
Is anyone else out there running an alloy 'VH' with a 28mm concentric '928' carb and a 7.5:1 piston . . What carb settings are you using ??
Getting there slowly
My avatar shows the late Len Rich in 1970 with the bike I now have - a 1958 Ariel VH