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#84383
If you disconnect the throttle cable from the carb, and the slide is able to move up and down freely, then it's a cable operation problem. It could be kinked, binding or snagging on something, or there could be some corrosion after thirteen years, presuming it's the original cable. Replacements are cheap enough.

As a matter of interest, what carburettor do you have fitted? If it's an Amal Mk1 concentric it could be over-tightened at the mounting flange, which can distort the carb body. If it's the original VM28 Mikarb it might just need a clean out.

A.

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