This is the clever and distinctive mechanism fitted to Norton roadgoing single cylinder models that were fitted with Amal 276 (seperate floatchamber type) carburettors, from the early 1930's to approximately 1955. This mechanism allowed the throttle to be lifted easily for cold running. The assembly consists of adjuster, adjustment block and screw and spring. This is the later type - with 1/4" BSW thread - see listing for more detail.
Price is Per Assembly
These assemblies are manufactured for us in the UK, to the original dimensions - which were adopted from (approximately) the late 1930's - at which point the orginal design was amended - to adopt a coarse 1/4" BSW thread, which our type also use.
The assembly consists of a cadmium plated shaft with a T-Bar (and the coarse type thread), a specially milled/shaped block with a small round head adjustment screw (whcih are dull nickel plated as per original) and a spring.
In operation - this design allows the throttle stop adjuster to be adjusted (via the small lockscrew and milled block), so that when the block is facing backwards, the throttle slide is in its normal 'Warm' running condition . . . but when the T-Bar is turned clockwise, so the milled block is facing forwads, it raised the throttle slide sliightly, which allowed the rider to easily set it in this position when cold, and get a fractionally faster idling speed.
To our knowledge, these assemblies were only fitted to Norton roadgoing models, but would be pleased to hear from anyone, if they know different!
PLEASE CHECK your carburettor body 'Throttle slide adjuster thread' before purchasing this item - as mentioned above, our units have the later '1/4" BSW (coarse) thread. Earlier original 1930's Norton 76/276 carbs were fitted with a finer 1BA thread. We show an original 'fine thread' type in one of the photos, so you can see the differnce - but we have no plans to make this earlier variant ourselves, as supposedly they do not work as well - because the fine thread did not move the slide up enough.
We cannot recommend it - but have been told that some people have tapped out the original early thread, to a later coarse type - THAT IS A CHOICE THE CUSTOMER MUST MAKE THEMSELVES, WE CANNOT RECOMMEND IT