Norton 650 Parts & Spares
The 646cc twin is what the Dominator grew into before the Atlas stretched it again, and in 650SS form it is the quickest of the Featherbed Nortons rather than simply the largest. Most of what it needs is shared with the twins either side of it, which is good news right up to the point where a bore-related part turns out to be listed for the wrong capacity.
We hold the 650 as part of the wider Norton twin range, so a component missing from this page is often sitting under the Dominator or the Atlas.
650SS, Manxman or Mercury?
All three are 646cc twins, and they differ in state of tune and equipment rather than in architecture. The 650SS is the sports machine of the group, the Manxman was an export model, and the Mercury came later and more plainly equipped. Cylinder heads, carburation and instruments are where they part company; crankcases, the AMC gearbox and the Featherbed chassis are common ground. Because the same engine also appeared in smaller and larger capacities, order top end parts against the engine number rather than against the frame.
Parts groups
- Top end — pistons and rings, valves and guides, head and base gaskets
- Bottom end — bearings and bushes, oil system and timing components
- Gearbox — AMC box internals and gears, clutch parts, sprockets and chains
- Electrics — ignition and charging components, lighting, switchgear
- Chassis — brake parts, fork and shock components, cables, fasteners
Engine and frame from different bikes?
It happens on these more than on most, and a logbook will not always admit it. Send both numbers and we will tell you which parts follow the engine and which follow the frame, and say when a measurement is the only way to settle it.