Translations:KAVAN S15-S180A/R FS30-FS180AR - Instruction Manual/70/en

3. Finally, inject „straight“ fuel (containing no nitromethane) into the engine. Crank the engine several times by hand to make sure it turns freely, and then crank the starter for 4-5 seconds to ensure that all friction surfaces are lubricated. If you are using a nitromethane containing fuel, this flushing with non-nitromethane fuel is a very useful habit to eliminate the corrosive effects of incompletely burned fuel residue that would otherwise build up in the engine.