I have a problem that is driving me nuts. I have a '84 K100 2v that I've written on before on this forum. Much of the electrics have now been sorted and I still have to attend to the gear box (2nd gear slipping out). But, I have a persistant flooding of cylinder No 1. Some times the bike will start perfectly; although the mixture tends to be a little rich (petrol smell). Most times however, the bike will start and idle badly (3 cylinders). Coaxing the engine along (stationary), it will take a while for cylinder one to catch up; usually accompanied by clouds of petrol smoke; back firing through the exhaust; and then settle down. Start her again (hot or cold) and she starts normally. Then (more times than not); it is the 3 cylinder start and the hassles to get her to idle normally.

This has got so bad that the bike has left me stranded on the road; necessitating the replacement of the plug to get going again.

Plugs are new; plug leads are new; coils are orange tipped and operating within their design range. All electrical contacts have been cleaned and cleaned again.

Where do I look?

pull the injectors and see whats happening with them ...do they spray correctly ....is the number 1 actually closing ...or leaking

The injectors is where I'd be looking first. If you haven't had them serviced then it would pay to have them done.

The #1 injector may be sticking open when cold.