Translations:KAVAN S15-S180A/R FS30-FS180AR - Instruction Manual/32/en

From KAVAN RC Wiki

Flushing four-stroke engines: flush again with kerosene, which we pour through the spark plug hole and a small amount into the drip nipple on the crankcase. Carefully turn the engine over, pour out the kerosene and repeat 2-3 times.