In article , snipped-for-privacy@false.email (Spozza) growled:
The engine is tending to stall at low revs, particularly when warm: I
> adjusted the carb so that the idle stopper screw was running at LOTS of
> revs with my foot off the throttle, so it stopped stalling. Mostly did
> this cos it's one of the few adjustments I know how to make correctly :) >
> There is slight popping and misfires at low revs, and the engine temp
> reads higher than 1/2 way but not in the red (could be an eletrical,
> don't know if I trust this). Starting the engine is usually accompanied
> by a puff of white/grey smoke, does this indicate anything?
The last of these is just worn valve guide seals. A common problem. Oil drips down onto the top of the pistons when the engine is at rest and then burns off when you start up. Eventually you'll need to replace them.
As to the main problem, have you done the basics: checked the state of the air filter (I got mine full of water once), checked the points, changed the spark plugs lately, or at least checked their gaps, got enough oil and water?
Once you've done all that it's time to look at your timing, which I have a suspicion may be where the problem lies, but there's not much point in starting to set that until you've got all the basics right.