Fitted the replacement earthing strap (but in a new location), the countersunk screw provided, and a few dabs of insulation paint just to secure the screws

Closeup shot

these are the old bits removed...

Finished job - started first time and sounded good. Will check the timing with a strobe next

Old coil replacement next on the list.

Replacement Flame Thrower coil and old unit

New one fitted - bracket reused ok but top connector on kinglead different (new one is push fit not screw in acrorn type

BEWARE - don't leave too much slack in the cables or the rotating spring posts could wear through the live wire, stop the engine, and create sparks - I know...

repaired (and now shorter) wire

setting the timing - a bit fiddly getting into the flywheel to check marks

AAARRRGGGHHHHHH !!!! This crack (shown in a mirror) in the back of the engine block was not expected and not part of the master plan... to be continued....

more

closer

it's down there somewhere

next night - cleaned it up, ran the engine, looks like it might be head gasket after all !!!

coolant running down the "crack" (probably a casting mark)

Before the digging starts

Air filter and oil bath off, ignition next

carb off, senders out, stud being removed from stubborn thermostat housing

some debris partially blocking coolant channel at base of thermostat housing

almost ready for lift off (just rear oil feed pipe and bolts to go)

next evening and the head is off

bypass hose almost blocked with rubbish

all looks ok

evidence of leak at the back of the gasket

can't really see the seat of the exhaust valve

typical bore - some wear in the cylinder but generally ok

closeup of the head where the leak was. Yellow'ish stuff may have been burnt oil when the gasket was smeered with oil on fitting? Doesn't look like sealer.

a couple look like they've had helicoils?

looks like some blow-by in a few places