Racing aluminum big bore cylinder 54mm for yamaha jog 90 2 stroke 4dm @tw 2 stroke 90cc air cooled horizontal engine atv / scooter. Yamaha JOG 90 4DM and Minarelli. 1x piston kit (12mm wrist pin). This item is in the category eBay Motors\Parts & Accessories\ATV, Side-by-Side & UTV Parts & Accessories\Engines & Engine Parts\Other Engine Parts.