TBW9150 Kit Consists of TBW1027, TBW1041, TBW1032 TB Parts 186cc Big Bore Performance Kit (64mm) – Grom: – Ceramic coated all aluminum cylinder (no steel sleeve) – Lightweight 64mm piston with rings, pin, clips – Head gasket kit This is the biggest Grom Monkey 125 bore kit on the market! The all aluminum ceramic coated cylinder is lighter than a steel sleeved aluminum cylinder, reduces friction (increasing power), improves sealing, and provides better heat transfer (runs and cools down quicker). This new big bore kit will provide the extra power to make your new bike a lot more fun to ride! High quality parts and requires no machining to the cases. There are no installation instructions, but if you can replace your piston, you can install this kit as the parts are installed in the same manner as the OEM parts. However, its recommended that a professional install this kit. It also must be used with an aftermarket fuel controller to prevent a lean condition and damage to your engine. This product is legal for closed-course competition use only; for racing vehicles (a competition vehicle not used on public highways). Intended for off-road use or race purposes; may not meet regulations of pollution controlled roads or highways. Not legal for vehicles registered and use in California. Check my other items. Can't find what you are looking for? Just type in what you need in the search box above and click search. Shipping: Calculated shipping and handling amount. Upgraded shipping available. Will ship multiple items for a reduced price. The more you buy, the more you save. All items in STOCK and shipped same or next day after payment Monday through Friday. Payment: IF BUYING MULTIPLE ITEMS REQUEST A TOTAL BEFORE PAYING! IF YOU DO NOT REQUEST A TOTAL AND MAKE PAYMENT THERE WILL BE NO REFUND. YOU MUST REQUEST A TOTAL BEFORE PAYING. PA residents must add 6% sales tax. Always include your FULL shipping address. All payment and tracking information is automatically emailed to you. Payment expected in 5 business days. Outside of US buyers are responsible for any tax or fees your country charges you, and no item will be shipped as a gift. Returns: 7 day return policy. No returns after 7 days from receiving item. Does not include electrical or engine parts. 20% restocking fee. Must be returned in original unopened sealed package. No returns on any opened, installed, or used part. No exceptions. Buyer pays return shipping and refund is for item price only, not shipping cost. Refund is store credit only.