Seeutek 26" or 28" 80cc Bike Bicycle Motorized 2 Stroke Cycle Motor Engine Kit Set 80cc bicycle engine kit with speedometer.This bike engine kit fits most mens' 24" and larger bicycles which includes mountain, cruiser, chopper and road bikes with a V-frame and at least a 8.5" height clearance for the engine. Larger frame size requires drilling into bike frame and use of the universal face plate. Large bikes (with larger frames/down tubes) may require the universal motor mount. 80cc bike motor kit, Mode of engine: single cylinder, air-cooling, 2-stroke; model of chain:415; chain length:110 links, 55 inches. Driving ratio:18: 01,fuel type:No.90;lubrication oil: motorcycle synthetic 2 stroke oil. Maximum Power: 2.2kW/600r/min; Rated Power: 1.5Kw/5000r/min; Horse power: 2.75 HP. Ignition type: CDI. Engine Type: Single cylinder, air-cooling, 2-stroke; Chain Model: 415 heavy duty chain; Chain Length: 110 links Be assured the mixing ratio for fuel and oil:16:1 for break period (first 300 miles) / 20:1 after(18:1 is much better in summer because of the hot weather);air cylinder might take some time to adjust to the load. Thus to avoid possible complications for the motor, please limit the riding time to a maximum of 1 hour for the first few rides. For screw and bolts easily broken,we have upgraded premium quality hex socket screw and bolts to improve the performance.Notes:The rider needs basic hardware skills, tools,and around 2-3 hours for installation and fine tuning adjustments.If you don't have experience or the first time on installing the motor kit,before installing,please kindly read our instruction and search "80cc bicycle engine kit" on youtube,it will give a big help and troubleshoot a lot of issues during installation process.