Use of Belleville washers to avoid carb. flange distortion.

[jj.palmer]

This is a method that I use for fitting the Amal carburettor to avoid thermal distortion to the fitting flange; it allows the whole of the flange to thermally expand/contract rather than just the central area when normal nuts/washers are fitted and fully tightened, see attached.

Belleville spring compression washers are made from spring steel in the shape of a cone, a pressure is applied to the carb. flange dependant on how far the pressure nut is tightened. I normally tighten the pressure nut until I can forcibly move the carb from side to side and then tighten the nut a further flat ie ⅙ of a turn.

A pack of 10 Belleville washers can be purchased from ebay for approx. £3, not expensive, spec. that I purchased, o/d 16 mm, bore 8,2 mm, thickness 0,9 mm, they come in a variety of thicknesses for varying pressures.


John P.