Thought I'd take one last trip out on the S1 before SORNing it. In a short run out of no more than 20 miles it went from missing a little to being almost unrideable.

Symptoms:

- Tacho was unstable (and getting worse). Initially reading up to 1000rpm higher than a expected but later sometimes 3000rpm
- Though initially it would idle OK, heading home it needed to be held above idle to remain running
- With the ignition on and but the bike not running the tacho needle would also jump to a value
- Moving the bars or moving the loom near RHS of the headstock sometimes made the tacho needle jump

i had taken the tank off for some fettling of the mounts just prior to going out and the bike was running fine last time out. The tank vent line was clear and disconnecting it while running did not improve the engine behaviour

So I figure there is something electrical in the loom. Anyone had this before on a tuber and know any weak points or known problems with these symptoms

Ta.

I'll give you 50 quid for it Jez as spares or repair for mine.....

I thought I'd get in there first as there are some charlatans out there who'd offer you well below it's market value. I hope you look upon this generous offer favourably being a fellow white lightning owner.........Dave

Loose connection on the coil?

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08 Specialized Langster

Think I'll do some fault finding first......but if you'd included a couple of bags of Pickled Onion Space Raiders I'd have been biting you hand off......


First thing I checked when I got home (to the spark plugs at least). I'll whip the tank off next weekend and have a nosey at the other side of the coil. Could this produce the dancing Tacho needle?

.....bloody hate electrics snags.....

Could be the same,
viewtopic.php?f=8&t=21978

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The sound of a V-twin engine braking is music to my ears!!

That’s what I’m on about

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08 Specialized Langster

Thanks. Will have a look at the weekend

I got some new connectors, but still haven't fitted them, just used a ring connector and a nut, as suggested by Brother in Buells

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Wear the fox hat

Was your tacho erratic prior to identifying this?

Yes

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Wear the fox hat

I'll keep my fingers crossed that this is my problem too then . Thanks

Bearing in mind it was running ok before I faffed with the tank mounting rubber I wonder if I have disturbed the coil at the same time.

I wonder too...

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08 Specialized Langster

well there's a fair chance & it will be an easy fix hopefully

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Feros Ferio

Finally got round to lifting the tank this morning and it appears that the front coil connector was loose. Pushed back on and no tacho needle jumps and ran OK at idle (which it wasn't after the last ride). Good call Pash and Bonzo.

Hopefully all will remain well come March!