TOPIC:

The engine in the first picture is an '81 A3. The second picture is a late model made in 82 or after with the right hand side ignition pickups.

I though about converting my 81 to the earlier system as I put the engine back together. The timing shaft from 79 will work on the 81, but the shaft from an 81 won't work on a 79 as the right side cannot accept the timing gear. The best thing to do is find 79 cylinder bank and early type timing shaft, then you can install the pickup assembly and re-wire the bike with the early style ignitor.

If your 81 has a good ignition, then I would not change it to an early system. You can install new coils and remove the ballast resistor. If the coils, charging system, and overall writing condition is good the '81 ignition won't give you a problem. That igniter is very sensitive to the voltage it is supplied and the load it drives. If either the voltage or load change much at all the unit will not last. Keeping the electrical system in top condition is the best method to keep the igniter alive. I bought a spare reproduction from Lauri in Finland incase something goes wrong with mine.

All that side I'm pretty sure you can build an 81 engine with an early style ignition, you cannot build one with the later type because they changed the engine cases in 82.

Good luck.

Thanks for that have had some good replies and we are all coming to the same conclusion, basically to achieve it a different block, Pistons, rings, timing shaft, Pick up Assembly and Left hand casing will be required along with Gaskets. (costs are rising Lol)
I think it might be time to think about moving this motor on or part it, and patiently wait till an A1 motor comes along. Fortunately it is not my only 13 so not in a desperate rush. The bike is a long term project. Once again thanks for everyone's advice will continue with the rest of the re-build in the meantime.

Hi,

Zoso has an A1 engine listed for sale in the " parts " section of this site.

Just a thought.

Thanks was looking at that might have a chat with him as he is in Scotland recently local to England lol seen it on E-Bay.
Just wish I had access to the States lol America has a wealth of parts.

Nice collection, look awesome