February 2015 – August 2015

Quick description

This was one of my first projects ever let alone one I put real thought and effort into how the end result would come out. I purchased this go kart as a roller frame with a seat, working brakes and throttle cable from a close friend.
Little did I know before I began this build how far my curiosity to drive could push me to complete such a project.

The Challenge

  • Finding a quality engine that is known push itself yet not shorten its lifespan.
  • Understanding power to weight ratios and how that could affect safety.
  • Accepting my intelligence and not being afraid of not knowing what to do next.
  • Making clutch adjustments so that the engine could put down all the torque to the wheels.

My Approach

  • Reading about all types of user experiences people were having with different brands of engines.
  • Asking adults with more experience than me what size engine they thought would fit my age, weight and height group.
  • Work until I physically and mentally do not know where to go next and then ask my educated father what he thinks.
  • Scoured through online forums that talked about how to make clutch adjustments for best performance.
212cc
predator

First Iterations

  • I choose to go with a 6.5hp (212cc) Predator engine that I bought because I had a coupon for. Maybe not the best idea considering it was the cheapest engine on the market, but it only made the most sense for a middle schooler’s budget and it’s availability for parts and online help.
  • As stubborn as my younger self was, I made sure not to hesitate when it came to help. I let my dad take the wheel and show me how some things were done because I certainly did not want to put all this time into this project just to wreck it or worse, wreck myself.
ebrake2
ebreak3

Second Iterations

  • As time went on, I realized that often when I had parked my go kart in my backyard I would come back after a few hours and find that it had rolled 5-10ft from where I had left it. I knew this was probably because my backyard is on a slight slant.
  • I had to think for hours on a solution as to how I would prevent this from occurring ever again. After a couple weeks I figured out that I would need to build myself a parking brake of some sort. I suggested my user-friendly design to my dad and him being as outstood as he was, we had to grab the welder and give it a try right then and there.
  • We took a piece of scrap metal with a hook looking groove notched into it and welded it to a bolt that could pivot in front of the brake pedal. That way every time you hit the brake to the floor when you’re done riding, you can pivot up the newly-created lever and the brake cable would stay stretched out, causing the go kart to no longer roll.

3rd Iteration

After about a year of riding around, I was quite used to the power range the go kart had to offer and decided it was time to make it slightly faster:

  • I thought on it for a couple days what could make it faster top end for cheap
  • I decided to add an aftermarket air filter to allow the air-cooled engine to breath better especially when being thrashed in summer conditions. This also made the engine more responsive by increasing low end torque as the new filter would deliver the necessary air into the carburetor to get this go kart to launch from a standstill.

3rd Iteration (II)

I also knew that I wanted a more convenient location for an off switch so I didn’t have to stick my hand near the spinning clutch just to ground the engine for it to turn off every time I was done riding it:

  • I did some research and found that fighter jets have switches all close to their hands and I wanted the same sort of design for a more elegant user experience.
  • After drawing up some designs, I figure it would be best to place it in one of the precut holes in the steering wheel.
  • I did some eyeball measurements, head out and bought a slick silver looking switch. Sure enough it was the exact size I needed. Thanks to all the tinkering I did as a kid, I was able to wire it up with ease, test it and have it work like a charm.

Final Solution

This all began as a miniscule idea in my head ever since I was a child. I had always looked forward to building something motorized that I could call my very own. Although, I liked to think I knew it all I couldn’t do it if it weren’t for my determination and peculiar creativity.

If it wasn’t for my interest in my deepest curiosity there would’ve been no way that I could have problem solved to get through the issues that I had to the degree that I did.