carburettion: what*s this a symptom of then?

[tombeau]

Just noticed, whilst giving a hand signal , when I take my hand off the throttle the bike accelerates rather than slows down.
I'm guessing too rich somewhere in the settings?
Cheers,
Iain

[a10 gf]

? What carb

Supposing the wire is well lubricated, the spring in good condition, throttle free in the bore, and closes net when releasing the throttle grip, then you may have a float level\flooding problem.

[tombeau]

389 Monobloc well lubed cable, springy spring.
It's progressive and gentle but it is accelerating.
It doesn't show up in normal driving.
This actually makes me realise how well the bike is running...I'm getting fussy!
Cheers,
Iain

[beezalex]

Tombeau, are you running an auto advance unit?  What you're seeing sound like a symptom of a broken or escaped spring.

[tombeau]

Hi Alex,
No I'm running manual advance/retard
Cheers,
iain

[a10 gf]

Using the trusted elimination method, check float level & float needle, look for loose needlejet, needle or main jet. While looking at these things some other things may show up.

If nothing helps, call a medium, to try to get in contact with the friendly ghost who takes over the throttle