Velosolex/Solex General Information
Spark Plug -
all models (except Tenor / 8000) -
Champion L86 / L86C
Bosch W7AC , W8AC
NGK B6HS , B5HS
AC 44L, 44F
Marchal CR 36, V 36
Denso W16FS, W16FS-U
Fuel Mixture -
Always mix your fuel in a clean, separate container. Never add oil directly to the Solex fuel tank.
Models 45 cc, 330, 660, 1010, 1400, 1700, 2200 V1 -
3% , 33:1
4 ounces of oil mixed with one gallon of regular unleaded gasoline
Models 2200 V2, S 3300, S 3800, 4600, 5000, Micron -
3 ounces of oil mixed with one gallon of regular unleaded gasoline
Use semi-synthetic / synthetic blend 2-cycle oil.
Do not use full synthetic oil.
Avoid fuel that contains ethanol.
Use ethanol-free fuel.
Ethanol is not good for 2-stroke engines in general, and it deforms the plastic and rubber fuel system pieces, such as the fuel tank, fuel tank cap, fuel filters, pump membrane and plastic seating piece.
Velosolex Solex websites:
Solex 3800 USA by Brian Solex: 
Velosolex 4600 by Brian Solex : 
Solex 3300 USA by Brian Solex: 
"Solex 5000 USA" by Brian Solex;