how do i make lowtension start hotshot?

Ivor here from UK and I have been lucky enough to find an Amanco 2 3/4 open crank which has never been converted to high tension and I remember reading somewhere that the low tension can be by passed using a 6volt torch battery for starting but is it straight forward to do? I should add that I have yet to fetch engine

I assume it has a magneto on it presently? If so you need to disconnected it from the igniter to prevent damage prior to using a battery. You will need some sort of a coil, regular low tension coils can be had for $50-70. You may also use the primary windings on a high tension coil for this or I have seen the pull in winding for a starter solenoid used. Or you can make your own, search "homemade low tension coil" If you use a make-do or homemade coil the test to see if it will run the engine is to connect a ground, or earth I think you say over there? from the battery to the coil and then attach a wire to the other terminal and quickly touch it to the + battery post. A good coil will yield a nice hot spark when the wire is removed. A weak coil can be temporarily boosted with a 12V battery to start the engine but the set up will be hard on the points if run for long periods. Once you have assured that your coil has the ability to make a good spark the engine wiring is simple. Connect the - side of the battery to the engine block. Then run a wire from the + terminal to the one of the coil terminals. From the other coil terminal you go to the ignitor. Before you wear yourself out cranking you can test the ignitor for function by these tests. A- with the points open and everything wired up you should be able to remove either wire, ground or hot and touch it back and remove it without getting a spark. B-if that passes then close the igniter points and try again, and you shouldget a good spark when you remove the wire. Good luck with it.