Yamabiko ECHO SRM-3020TES Manuel D'utilisation page 15

Fuel
Fuel supply
Before you start
 Recommended mixture ratio; 50: 1 (2%) for ISO-L-EGD
Standard (ISO/CD 13738), JASO FC,FD grade and ECHO
Premium 50: 1 oil.
 Do not mix directly in engine fuel tank.
 Do not add so much fuel that it reaches the mouth of the fuel
tank (A). Keep the fuel within the prescribed level (up to the
shoulder level (B) of the fuel tank).
 Tighten the fuel tank cap securely after refuelling.
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