My KH has a Lucas K2FC magneto and so the ignition control is via a handlebar lever rather than an automatic timing device. The magneto failed due to heat the other day and although it sparked well enough to start the engine once everything had cooled down it really needs looking at. When I took the...

Roger's quite right that if the pitch is out the chain will ride up on the sprocket. However, if the tooth form isn't correct - effectively too long - the teeth won't disengage from the chain rollers correctly and 'hop' as seems to be happening here. If this is the case, the chain will similarly hop...

I don't share Chris's optimism. I'd check the tooth profile as it seems to
be late disengaging from the chain rollers. I might still have an original
unused sprocket somewhere . . .

Looking at an original cam the edges are not sharp as in the Draganfly version but neatly blended
into the radiused ends. The action with the Draganfly cam won't be very effective and I wonder
how quickly the faces of the brake shoes will wear.

Another cause of oil leaking is the state of the two flanges which prevent oil which is running down the inside walls of the chaincase from running out of the holes where the mainshaft enters. The flanges suffer if the cases aren't well aligned with the clutch chainwheel. The cork clutch isn't usual...

Have you considered the state of the chain oiler? My KH turned out to have the
wrong screw - no taper - in the oilar and could deposit large amounts of oil over
the rear chain and back tyre in only a few miles.

5/8" by 3/8" but a word of caution: spring links can be specific to the
manufacturer of the chain which is often stamped onto the sideplates
of the chain.

Looking at the user guide in the members' only document repository - page 6: http://www.arielownersmcc.com/members_only/ariel_library/DocumentRepository/Ariel/Ariel1954-55owersGuideKH/Ariel1954-55owersGuideKH.pdf It seems that the kill button was incorporated into the end of the magneto. Having said...

That's not a good idea. As and when the electrical tape frets through you will have a dead short to earth and without a fuse in the system you will have a fire on your hands. Similarly, the horn body only has to move slightly and touch the primary chaincase to cause problems. The fault will be insid...

I thought that the horn electrics were insulated from the horn body and mountings so that the horns
weren't polarity sensitive.

Internal short to the body perhaps?