Internal Fire Museum of Power

Roland,
Heaven forbid that a sparky should give you suggestions, but here goes anyway. Have you tried putting a few drops of fuel in the sparkplug hole. This would prove that the plug is capable of firing the mixture and that the ignition timeing is not far out. If you have good compression there can't be much wrong with the valves and seats.
Please excuse the audacity
Ewan

Are you turning it the right way Roland?

(ducks and runs)

NHH

All suggestions welcome. There are arrows on the flywheel and its run well in that direction . Yes it will fire if I put a sensible quantity of petrol in the spark plug hole. There is a seemingly good seal twixt port and manifold and it will suck my hand if I clamp it round the choke. I agree about the valves but I'm clutching at straws. Nex check is to pull the manifold/vaporiser and check for leakage between inlet and exhaust.
The key point is that it has run perfectly with everything set as it is now!

cheers
Roland

After a protracted session of carb flooding on the bike, involving a lot of repeated dismantling, I was amazed how much trouble a tiny (more or less invisible) bit of dirt in the carb could cause. I never found it but it finally went only after the third dismantle/clean/blowout with airline. It's been fine ever since.
You have my sympathy.

Flooding would be a step forward
Here is a pic - note the flywheel movement in case it never recurs!

As Eric warned it is filthier than an off-load Petter M!

cheers
Roland

This morning switch on fuel and wind. Floods. Change plug still floods. So put back original very tatty mag (Bosch 22 flick) with winding resistance of >200K ohms. Starts first rev and runs smoothly.
The spare mag looked and measured much better and seemed to give a better spark. It had also been given a clean bill of health by an expert. However further tests show it to be inconsistent. I'll send it off for a rebuild to http://www.magnetorepairs.com/index.php

I originally swapped the mags over when the real problem was obviously the lurking and minute rust in the jet.

Silly old fool
Roland

Roland,
You mean "Older and wiser"......?

E

Roland,

"Silly old fool" or "older and wiser" doesnt matter , you got it going which does so well done at least it was a simpe fix.

Martin P

Good to hear you sorted it.

Cheers Steve