Gasoline/petrol engine(5.5HP, 6.5HP, 7HP, 9HP, 11HP, 13HP) Specifications: Our ... 25, air cooled, 4-stroke single cylinder, OHV 25, air cooled, 4-stroke single cylinder, OHV 25, air cooled, 4-stroke single cylinder, OHV 25, air cooled, 4 ... -stroke single cylinder, OHV 25, air cooled, 4 ...