This is a Yerf-Dog 150cc GoKart that I converted to Electric Power. I’m using a Mars 0709 Motor, AllTrax 7234 72Volt Controller, and ThunderPower 72Volt 25AmpHour Batteries. With a 39 tooth rear sprocket and a 10 tooth in front I have a 3.9-1 gear ratio with 20″ tires. This system tops out at 300amps or around 28HP with a top speed of over 50mph!This is how it looked when I purchased it off CraigsList for $400. The Kart was is good shape except for the engine that needed the piston replaced.Here’s a picture of the engine and how it sites in the kart.And here’s how it looks after removing the engine.At this point I am in the process of completely disassembling the kart for cleaning and new paint.Here’s the start of painting. I used about a half dozen rattle cans of my favorite paint and made sure to hit it from every angle.At this point I have de-greased, cleaned and painted the entire kart. Starting to reassemble, with the front end and steering components.Rear end bolted back on.Ok I now have a nice clean platform for my electric components to ride in.I mounted the motor by strapping it between 2 main cross bars of the frame.So far the straps have held the motor securely even under the 28HP load.I would like to increase the gear ratio at some point but the 39tooth sprocket is the largest that will fit without cutting or moving the rear axle back.I used a 1/2″ board to mount all the Controller component on. I then strapped the board to the frame with some foam padding to give it some cushion.Here’s a closer look at how I arranged everything.As for batteries I use ThunderPower Lithium Polymer packs ganged together to give me 25ah at 72volt. These are batteries I use in my electric remote controlled planes.I am in the process of building a box for the batteries that I will mount underneath the back rack.I will be adding lights, seatbelts,better tires, a battery box, and graphics to finish out this Kart.
