Carburettor Velocity Stack - Fits AMAL 900 Series and Wassell

These heat treated, and glass bead blasted Aluminium velocity stacks are designed specifically for the 900 series Amal carburettors to be a VERY snug fit.  They come in LEFT and RIGHT hand twists, with pinch screws also entering from the left or right of the bike dependant on the model. 

The are clamped in place with one supplied M3 x15mm Caphead screw and spring washer. 

Should you with to use a panhead/cheese head screw they do also fit but some manufacturers have larger head diameters than others, so some light fettling of the screw head diameter may be required.

At 68g each there are incredibly light and flow exceptionally well

Compatibility

This part does not fit AMAL 200 Series, 300 Series, 600 Series, and 1000 Series carbs although I will soon have options for all those carbs!

Fitting the Stack to the Carb

Some sanding if the internal surface may be required for some carbs depending how high their tread is, they vary over the years. 

In my experience, with the M3 screw and spring washer removed, some force and twist will allow you to seat the stack so the base sits snug against the small AMAL flange at the base its air filter thread. Once the M3 screw provide some gentle resistance typically only a 1/4 turn further is all that is required!  DONT go nuts