Which brand of ignition is this ?

[Macbeth]

All I know is that it’s 6v. 1960 SR. The engine only has 20klm on it & running in just fine however I’m fouling plugs at 3 to 4 klm. Plugs are NGK B7ES. Being fed by mikunis that were cleaned. Idles & pulls very well until it fouls. So I read as much as I could & found some electronic ignitions need resistor plugs so yesterday I popped BR7ES in last night & the bike ran fine again just for 3-4klm.

The left cylinder seems to suffer the most. I’d say the builder has it running rich & im starting to think maybe it’s just too rich yet I’m very tentative to change anything before taking it back to him. Not sure if it’s maybe just richness. I’m tempted to just go for a new 12v system or would you think 1 step hotter plug may help ?

Reading more now. The petrol is exactly 12 mths old 🤔maybe ditch stuff that as job 1

[Macbeth]

Dang..just did another 4 klm & a plug chop as it died. Left seems to spark just fine with a cleaned earthed plug out of the head

[CheeserBeezer]

What plug gaps are you running?

[Triton Thrasher]

Problems of richness have to be addressed by reducing the richness.

[Macbeth]

What plug gaps are you running?

I’m a B***** for never gapping a plug because every time I attempt it - they are always spot on. All 3 diff sets that I’m alternating were brand new & I get the same result on the left plug. I also swap left to right once cleaned & same again