Right update on this.

I've just finished doing the re-wiring on the bike, but haven't had time to test it as it wouldn't run properly at all.

Had to pull the plugs and clean them up on the hob after cranking it on and off for about 2 minutes. They were wet with petrol so it's getting fuel.
Got them back in and she started up. Warmed up a bit so I let the choke down gradually and she idled okay but high, so I adjusted the idle down then gave her a little rev.

Was going to test Neo's air leak theory with some easy start around the carb rubbers but she didn't want to rev past 5k rpm and even when held at 5k she slowly died, sounding as though she was only running a couple of cylinders. Exhaust smelt like fresh petrol and plugs were wet again (rear ones anyway).

I think the plugs have about had it, would I be right?

the slowly dying makes me wonder about whether it has the power - can you test this with a piggy backed battery/via jump leads?? It will eliminate your electrical problems.

Plugs could easily be dead..sounds like they are being drowned!

No I don't have another battery to do that with, or jump leads for that matter unfortunately.

The battery was fully charged and still happily cranked the engine over after it died.

I've put the bike back to rest in the garage for a while as I was getting grumpy, add that to being tired from an early start and hungry as tomorrow is shopping day, it's probably best I don't touch it until tomorrow.

I feel your ballache mate. Nothing pisses you off more than recalcitrant machinery!

Can it hold a steady 3k revs on the idle adjuster rather than the choke? get it hot if you can and see if that helps.

Are you taking it out for trundle in between playing about? there could be just unused fuel in the engine thats playing it up. Try taking it round the block and get some load on it, you cant set bike carbs up by just blipping the throttle.
Cheers
Ian

You have a point, and no I am not.

I shall get it warm later as Mark suggested then take it over to my Mums for a good run and see how she does. I think I'll be taking my tools and charger with me though

Right, currently at my Mum's, did as you suggested Mark and let the bike idle at 3k rpm until it got most of the way to the right of the temp gauge then wacked on the fan to let it cool a bit before turning it off. I'm also currently sat here with two burnt fingers after catching them on my exhaust

The bike struggled a bit at first, sounded like it had a slight mis-fire on one or more cylinders but once it got hot that went away. So got on the way here and it felt fine, pulled well in every gear and sounds great
It's got a nice little crackle on the over-run.

I'm now confident it has an air leak somewhere as the idle is still a little unsettled and sometimes rises on its own. But I'll still test it to make sure, just lucky I have spare carb rubbers

Also tested the voltage across the battery as I've done the re-wiring and my dodgy wiring was at fault. Battery reading slowly went up as the bike charged it and was at 14.7volts when I last read it as I was satisfied with it.

Awesome....I am so good, I amaze myself!

Neosophist wrote: I still think you have an air-leak and / or somethign else.

Dont forget electrical issues will cause shitty running too.

between 1.75 - 2.5 you should really notice a great deal of difference, certainly not enough to kill the bike.

Did you test it for air-leaks? I wrote somewhere a quick way to test..

with it idling spray something flamabble like carb cleaner around the rubbers and if you notice a change in rpm theres a leak as it will suck the flammable stuff in..

Revs increasing on their own is airleak sign too.

Dont forget you can leak air throgh the balance take off points and vaccum pipe but since your revs sometimes rise im 99% sure that what I said first, carb rubbers are leaking, occasionally they will seal and stop leaking which is why you get shitty idling.

Are they old rubbers? For the sake of all the hassle, time and effort if they are just get some new ones for around 20 quid and it will solve all your issues for the next 20 years.

Im coming to this thread a bit late and if this has been covered then move along.. Have you checked that the earth plate on the nearside of the frame is making a good connection???

I remember last year when it was service time I had removed my crash protectors that hold the earth plate to the frame and when I was starting the engine it was running like a dog one minute and then perfect the next, after much head scratching I remember that I had not re earthed the plate ...