Hi FOlks
I finally got round to charging the battery (no difference) and replacing the plug (with an Iridium BR9EIX 3981) as suggested. Managed to kick-start it first time, but subsequently not able to do it again.
I removed the primary cover and there was no sign of any debris - the cog from the starter looks fine from what I can see of it. Here's a pic:
http://www.interxmedia.co.uk/?p=160
Put it back & replaced the oil with 15w40.
Still no luck with kicker, but it starts 50% of the time with the electric start the other 50% of the time it doesn't engage with/turn the engine, and often makes such a horrible clackety-clack that I am worried something is getting smashed to bits.
I asked my local garage if they would replace the sprag (if it is indeed broken - I think so but how can it start the bike some of the time quite happily?) and they said it wasn't worth it - just as many of the folks on this forum...
I am still not clear if replacing the (original black) TCI with a green one (are they still available) or a Hitchcocks upgrade would help fix the problem so I could replace the sprag if needed.
If I can't use the electric start and I can't reliably kick-start then I am in trouble
Currently this is my (mostly unsuccessful) kick-start procedure:
1. switch on fuel and pull out choke (it doesn't start at all without choke)
2. pull clutch lever and kick it over a couple of times
3. pull the decomp lever down - it only goes half-way at this stage and doesn't seem to have much effect - and push on kicker for a minute or two until it starts to turn.
4. return foot and kicker to top and hold decomp lever down until motor starts to turn again - at this point the decomp lever moves all the way down and feels like it is working.
5. release decomp lever, return foot and kicker to top and kick down.
...at this point it may start or more likely it will just turn over without starting but also quite often it will go 'clack!' and kick-back.
I could really use some help on this as I am stuck with a bike I can't really use at the moment - either I need to get it kicking reliably or I need to get the electric start working safely - or preferably both! I can't even cut my losses and sell it to go back to a jap bike as no-one will want a bike that won't start and makes noises like it is self-destructing...