ECCENTRIC ROCKERS
Valve clearance adjustment by rotating eccentric rocker spindles was seen on NSU and Velocette engines in the 1930s before its adoption on the AJS 7R. It makes adjustment easier; it is carried out here by releasing locking tabs and using a simple tool that fits notches on the ends of the spindles. The system also avoids the undesirable reciprocating weight of adjusters on rockers or tappets, allowing higher rpm without valve float and reducing stress in the valve gear.