Basically my first post so Hello and thank you for this site as it has saved me numerous times

Currently I have a Aircooled CU on the drive, I was meant to be taking it to JRP Welding today but after being stood for a month it seemed to have developed a missfire. I managed a mile down the road but couldnt get up to a decent speed!
So on the drive I checked the fuel lines, pump and filter. Lines and filter seem fine and pump buzzes on ignition.
Checked vacuum hoses and they all seem fine (as far as I can tell)
Earths and wiring seem fine but will check again in a mo
Checked spark on cylinder one and had that. Then I realised it was coming from the right hand side of the exhaust only so I took the lead off plug two and it stopped, plus there was no change in the engine level. This seemed weird to me so tried it again and the missfire def stopped when I took the lead off.
However, the engine then cut out and now it wont start again, we have spark from the coil to the dizzy, the rotor arm is spinning and when we held the coil HT lead over the middle of the rotor arm there was no jump so the rotar arm seems to be working as it should. But there is now no spark at 1.
I have replaced the dizzy cap with a new BERU one and have a rotor arm on order to try tomorrow morning.
The little black box with two plugs by the coil has already been bipassed so I assumed I can rule that out. Would I be right in saying its either the hall sender or ignition module. My only confusion comes from reading that the hall sender sends a signal to the coil, so if I am getting spark at the coil then does that not mean the hall sender is still doing its job.
Cheers
Ellie