The original switched charge control was pretty poor and it wasn't uncommon for owners to swap the alternator coil pairings to increase the charge at low revs. This had the effect of boiling the battery on a longer run with the displaced acid eventually rotting out the battery support, the front par...

There isn't much in common between an HT and a road-going Ariel - the frame, forks, gearbox, swinging arm, back wheel, oil and petrol tanks are all special. I've only knowingly met one HT3 and that was in darkest Oxfordshire a very long time ago. I never really saw the point with the 350 weighing pr...

What voltage is the battery and do you know if a previous owner has fitted an electronic
regulator?

The original rectifier lived behind the drive-side tank badge. It's actually a bridge rectifier
and a little patience and a multimeter should show which if any of the diodes are
leaking.

Arrow and Leader electrics rely on the rectifier to prevent the battery discharging. The only regulation of battery voltage comes with switching pairs of alternator coils into circuit when the headlamp is switched on. The original rectifiers fitted to the Arrow and Leader had a short life and this i...

The first five-stud alloy barrels had a reputation for weakness at the flange. I was told that 7:1 was a high as you wanted to go and anyway with the spark plug coming in at such an angle the combustion shape needed a vast amount of advance so there was no point. vha_9.jpg Not one of mine. It was ad...

The need for a thicker gasket suggests a lack of clearance and, if the camshaft isn't too long, then it suggests that there is an issue with the bushes being effectively too close. This may be because one or both have moved in their housings or that one or both housings have been damaged. Given that...

Yes it is rather good stuff.

Once Roger gets on with the challenge there will be a broad path
worn to his workshop by Arielists bearing magnetos, me included.

I don't remember ever having issues with no endfloat on a cam but I have had
issues with the bushes not aligning when swapping timing chests.

I put a vernier across a known good camshaft and got 1.685".

It's possible your performance cam has been built up and not done well.

Back on the subject of clutch springs I've had a try at comparing my 92-R spring with a brand-new Draganfly 3405-54. These latter are significantly stronger than the Burman cork clutch spring 3405-36. 5mm compression on the Draganfly spring produced 3mm compression on the 92-R spring with 10mm produ...

A quick and not especially accurate measure of my clutch springs gives 6 turns wound left-hand with 16swg wire with an OD of 1/2" and a length of 15/16". My springs may well have settled over time but are more-or-less the same as your shorter spring. The Burman part number is 92-R which do...