Seeutek PK80 80cc Bicycle Engine Kit 2-Stroke Gas Motorized Bike Motor Kit Upgrade with Speedoemter 80cc Bicycle Engine Kit,Engine Type: Single cylinder,air-cooled,2-stroke.For screw and bolts easily broken, we have upgraded premium quality hex socket screw and bolts to improve the performance. Motorized bike kit,Power: 5-6 HP (horse power) stock -Top Speed: 25-35 MPH (miles per hour) stock - Fuel Economy: 100-150 miles per gallon Fuel Type:Gasoline 93#;Mixing Ratio of Fuel and engine Oil: 16:1 for new sets breaking time, 25:1 after running 300KM;Please use premium quality oils to prolong engine life. And add some lubricant into the air cylinder before starting. Bonus Speedometer as gift,Fits Most 26" Wheeled Bikes (Mountain, Cruiser, Chopper, Road) with V-frame. The frame should have 9-11" of clearance between the bottom bracket and top bar, and the diameter of the frame tubes should be 25-29mm (around an 1"). Notes:The rider needs basic hardware skills, tools, and around 2-3 hours for installation and fine tuning adjustments. If you do not 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.