{"product_id":"mc623000","title":"Four-Valve Head Kit","description":"\u003cp style=\"text-align: left;\"\u003e\u003cspan\u003eOur Koso 4V Head Kit is the ideal engine part to complete the Koso Honda Grom® Big Bore kit. Because of its unique 4 valve design, the air flow and performance are increased. This new designed head is the perfect addition for those who desire more power and torque. The 4 Valve Head Kit features a forged piston, stainless steel 24 mm intake valves and 20 mm exhaust valves. \u003c\/span\u003e\u003cstrong\u003eOnly fits Koso 170cc big bore kit\u003c\/strong\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003eWARNING\u003c\/h2\u003e\n\u003cp\u003eTHIS IS AN AFTERMARKET PART BUILT FOR RACING PURPOSES ONLY. KOSO IS NOT RESPONSIBLE FOR ANY DAMAGES CAUSED TO THE PARTS, VEHICLE, OR TO YOURSELF AND OTHERS.  ENGINE PARTS ARE NOT UNDER WARRANTY NOR IS COLLATERAL DAMAGE OR COST OF LABOR, IN CASES OF MALFUNCTION.\u003c\/p\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinder height:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e64.2 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGasket thickness:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eUpper: 0.25 mm | Bottom: 0.5 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePiston compression\u003c\/strong\u003e: height: 19.5 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVolume:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e169.21cc\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSquish:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e1mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinder head titration:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e13.4 cc\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompression ratio:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e12.3 : 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eValve \/ Tappet clearance:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eIN: 0.10 mm EX: 0.17 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamshaft: Torque:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e1.71 Hp: 26.26\u003cspan\u003e \u003c\/span\u003e\u003cem\u003e*measured without air filter \u0026amp; no noise reduction plug\u003c\/em\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e**Requires the use of Iridium spark plug:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eNGK‑ER9EHIX (part\u003cspan\u003e \u003c\/span\u003eNGK-ER9EH)\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFits for Honda Grom\u003cspan class=\"s1\"\u003e®\u003c\/span\u003e \u0026amp; Honda\u003cspan class=\"Apple-converted-space\"\u003e \u003c\/span\u003eMonkey\u003cspan class=\"s1\"\u003e® up to 2021\u003c\/span\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Koso North America","offers":[{"title":"Default Title","offer_id":43976585445419,"sku":"MC623000","price":937.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0598\/7830\/9931\/files\/E27F3AD4-48AA-4666-9EC1-11069CEECB91.jpg?v=1776736740","url":"https:\/\/www.74motorsports.com\/products\/mc623000","provider":"74 Motorsports","version":"1.0","type":"link"}