When all 4 cylinders are connected, the bike is reluctant to start and if it does, only run on three cylinders. If one of the rear cylinders is disconnected (plug cap removed) the bike starts easier. It doesn't seem to matter which rear cylinder you disconnect, but it won't run on 4. If you warm the bike up and try and ride it, it runs very badly, on two cylinders it seems.

Anybody any ideas? Also a cheap Haynes manual and many other parts for the bike are required if anyone needs rid.

Thanks!

Crap battery? Does it matter which plugs you remove?

Check the rear coil;earthing to the frame and terminal connections.
Try swapping the front and rear coils to see if the problem goes with the coils.

Have you checked the charging voltage ?

regards
jon

With a different plug in the cap (we don't have a deep enough socket to get the bastard plugs out) you get a good strong spark from both sides so do things like earths, battery voltage etc still apply?

So both cylinders have a spark.

Also I'm reading again and again that it should start with no throttle, just choke, but mine needs a touch of throttle. Probably the least of my worries.

With the airbox off, looking at the slides, they're fluttering and opening very slowly, and never fully opening even at full throttle. Perhaps another, unrelated problem though.

Hiya, your gonna have to buy a plug spanner or a deep socket, the plugs are tiny and flood really easily(sorry i cant remember what size socket youll need). When you get the plugs out heat the electrodes up with a blow torch or gas cooker to burn off the petrol and maybe give then a wire brush, if not just buy some new ones. I'd put money on it been dodgey plugs.
Cheers
Ian

It is always dodgy plugs.....

Will burning the petrol/oil off be as good as new ones? Could do without being another £40 out of pocket. If anyone wants to swap some used NC30 plug for some used nc23 iridium ones that'd be really helpful!

When carb cleaner is sprayed into the most suspect cylinder revs rise. Sprayed into the others it has little effect. Cleaning the carbs thoroughly hasn't helped.

Still waiting for new coils but after that I have no idea?!