How I turned a rust bucket to 100 km/h speed machine

When I was younger, my dad made two 6.5 horsepower go-karts for me to drive around. The karts were really fun but as I got older and a better driver, I found them too slow and boring and outgrew them. I ended up selling them on Craigslist but then found myself longing for the speed and rush of driving a go-kart. One day my dad came home and told me he saw an old racing go-kart for sale in someone’s backyard. This was my chance to regain that exciting go-karting feeling again. But the go-kart was broken down. I’d have to rebuild it myself.

The idea was a bit daunting. After all, I hadn’t really done anything like this before. But my dad has loads of mechanical experience and was always buying junk cars and rebuilding them, so I knew I’d have support when I needed it. I decided to go for it.  

After taking the go-kart home for only $250, I did some research and figured out I had bought a 1980’s Yamaha Go-Kart with a KT100 2-stroke engine, that made 15 horsepower at 10,000 rpm. The go-kart was apparently capable of going up to 100 kph. For a go-kart, that’s fast! My first go-karts that could only go 40-50 km/h.

When I got the go-kart, it did not run and did not roll. It was rusty and missing parts. The back half of the cart was a mess of rust and ugly paint.  It was missing numerous bolts, springs and even half the motor mount. This would take a lot of work.

So the first thing I did was make a checklist of the things I needed to do. I had to get the engine rebuilt, sandblast and repair the body, completely rebuild the brake, replace the front and rear bearings, repair the starter motor (which turned out to be a V8) and build the bottom half of the motor mounts. It was a lot of work but i was ready for the challenge.  

The first thing I tried to do was get the engine started. This was surprisingly easy but the engine was on its last legs and had really low cylinder compression. It only had 80 psi, which is the bare minimum it needs to run at all,  so it had almost no power. It was unreliable, weak and would not stay running. It would fire once and then it would stall. We ended up sending it off to a place in Indiana called Comet Kart Sales to get it rebuilt.

While the engine was off in Texas being rebuilt, I started working on the other stuff, like painting and replacing the bearings and brakes. The go-kart was covered in rust and cheap old paint. The only way to get this off was to sandblast it. I bought a sandblaster and I tried to sandblast it myself it the backyard, though it was probably one of the worst ideas I’ve had. It took about 8 hours to completely clean the Kart, chrome, and black bits. I learned my lesson, I won’t do that again. All of the bearings were shot, loose and missing seals, so we were forced to replace them. The brake was completely seized, leaking and almost unidentifiable. It took two days of research to even figure out what brake I had and get the proper rebuild kit. It ended up being pretty easy and quick to disassemble and clean. It only took me 30 minutes to reassemble. It was about this time that I got the engine back.

I was super excited to finally get the engine back so I slapped it on and tried to start it right away, but it wouldn’t work. I tried unsuccessfully for about three days. It turns out that my go kart was one of the original karts which mounts the engine backwards compared to modern go-karts. Mounting it the wrong way around meant that the spark timing was 180 out of tune, which is why it wouldn’t start. As soon as I figured this out, I made the necessary adjustments and the engine started right up.  

As I was breaking in the engine, the chain exploded. That scared me pretty bad, though miraculously it didn’t break anything. This is when I decided to get a new chain and put on a chain guard on the kart to protect myself from any other issues it might have in the future.

After all the struggles and near death experiences, it was finally ready to try to kill me once again. It was time to take it out for a spin.

The first time I drove it, it was amazing. I did notice that the bottom end of the rpm was pretty weak but once you got into the middle range it really started to pull. I know I didn’t get it up to 100 km/h but it was still frightfully fast. I took it out by my house and raced it up and down the alley. This was first time I really noticed how low it was to the ground. My seat would scrape on everything. I tried to drive it up over a small lip in the road to gain access to the alley but the front bumper hit the lip and stopped me right in my tracks. This was just something I would have to get used to because it’s supposed to be like this–Go Karts are made for race tracks, not the street. But i took it out a couple more times and i started to get used to the speed and found it more fun than terrifying.

Two years later it still runs and drives perfectly. Unfortunately, where I live, it rains more than half the year so it is difficult to find a good time to take it out. I keep it in my friend’s underground parking lot for the rainy months and bring it back to my place for the sunny ones. But overall, I’m happy with my go kart and would recommend making one to anyone looking for some fun or anyone wanting to learn some mechanical skills. I also highly recommend it to any teenager looking to scare their mother senseless.