Motor Cycles - AJS to Douglas |
| Manufacturer | Model / hp | Spark Plug |
| Manufacturer | Model / hp | Spark Plug |
| AJS | Side Valve Models 18mm | 7 | Brough | Other Models 14mm | L-10S |
| AJS | Side Valve Models 14mm | L-10 | Brough | Side Valve Models | 7 |
| AJS | OHV Models 18mm | 16 | B.S.A. | All Side Valve Models 18mm | 7 |
| AJS | 1946 350cc | L-10 | B.S.A.Bantam | 125cc C/Iron Head | L-10 |
| AJS | 1946 500cc | L10S | B.S.A. | C10 M20 M21 C/Iron heads | L-10 |
| AJS | 1947-49 Cast Iron Head Models | L-10S | B.S.A. | C10 C10L M20 M21 Ali Heads | N-8B |
| AJS | 1950 Onwards Ali Head Models | NA-8 | B.S.A. Bantam | 1954-on D1 125cc D3 150cc | L-10S |
| AJS | OHC Model 7R Racing | NA-14 | B.S.A. | C11 C11G C12 B31 C/Iron Heads | L-10S |
| Alcyon | Side Valve Models | 15-A | B.S.A. | B33 M33 A7 A10 C/Iron Heads | L-10S |
| Alcyon | OHV Models 18mm | 17 | B.S.A. | B32 B34 Gold Flash C/iron Heads | L-10S |
| Alcyon | OHV Models 14mm | L-10 | B.S.A. | A7 Star Twin | L-10S |
| Ambassador | 197cc Villiers VIE | L11S | B.S.A. | Gold Star B32 and B34 Ali Heads | NA-8 |
| Ambassador | Envoy Supreme Embassy Popular | L-11S | B.S.A. | Gold Star Racing | NA-14 |
| Ambassador | Zundapp engined models | L-10S | B.S.A. | Gold Star Scrambler | NA-12 or 12 |
| Ariel | OHV Models 18mm | 16 | B.S.A. | A7 Shooting Star | NA-10 |
| Ariel | Side Valve Models 18mm | 7 | Commander | 98cc Villiers | L-10S |
| Ariel | Side Valve 14mm 1/2" Reach | L-10 | Commander | 122cc Villiers | L-10S |
| Ariel | Square 4 Cast iron + Mk1 Alloy | L-10S | Cotton | Side Valve | 7 |
| Ariel | Square 4 MkII Alloy | NA-8 | Cotton | OHV 18mm fitting | 16 |
| Ariel | OHV Models Cast iron 14mm | L-10S | Cotton | OHV 14mm fitting | L-10S |
| Ariel | OHV Models Ali Head +600cc VB | NA-8 | Coventry Eagle | OHV 14mm fitting | L-10S |
| Ariel | HS Scrambler | NA-10 or 12 | Coventry Eagle | OHV 18mm fitting | 16 |
| Benson | 125cc | 8 Com | Coventry Eagle | 125cc 18mm fitting | 8 Com |
| Bianchi | 125cc and 250cc | J-8 | Coventry Eagle | 125cc 14mm fitting | L-10 |
| Bianchi | 250cc Sports | J-6 | Coventry Eagle | 147cc | 8 Com |
| Bianchi | 500cc | 17 | Coventry Eagle | 197cc | L-11S |
| Blackburne Engines | Side Valve Models | 7 | Csepel | 125cc 250cc | L-10 |
| Blackburne Engines | OHV Models 14mm | L-10S | Dayton | Albatross 225cc | L-11S |
| Blackburne Engines | OHV Models 18mm | 16 | DKW Auto-Union | 18mm fitting | 17 |
| B.M.W. | R17 R57 R63 | 7 | DKW Auto-Union | RT125 | L-10S |
| B.M.W. | R4 R11 R16 | 17 | DKW Auto-Union | RT3 RT100 | L-10S |
| B.M.W. | R2 R3 R6 R12 R20 R23 R35 | L-10S | DKW Auto-Union | NZ350 | J-6 |
| B.M.W. | R36 R37 R61 R71 R75 | L10-S | D.M.W. | 125cc 150cc | L-10S |
| B.M.W. | R24 R25 R25/1 R25/2 R25/3 | L-11S | D.M.W. | 197cc 225cc 250cc | L-11S |
| B.M.W. | R51 R51/2 R51/3 R66 R67 | L-11S | D.M.W. | Hornet 125cc | L-11S |
| B.M.W. | R67/1 R67/1 R68 | L-11S | Dot | 197cc and 225cc | L-11S |
| Bown | 122cc Villiers Engine | L-10S | Dot | Scrambler (Tuned) | LA-1 4 |
| Britax | Hurricane | LA-11 | Douglas | 150cc | 8 Com |
| Brockhouse | Indian Brave | NA-8 | Douglas | 250cc 14mm | L-10 |
| Brough Superior | SS100 from 1934 | N-8B | Douglas | 250cc 18mm | 7 |
