The World's Fastest Coin Operated Ride

The Story

My First build. Starting building back in 2019 in half of an open garage in a share house and has now become one of the craziest builds on the planet. I had no intentions of building a go-kart let alone this. I didnt even own a welder or a grinder, just some basic tools. I had seen the original ride up for sale on marketplace for $250, the moment I saw it I thought, "This would make a pretty cool go-kart". So I bought it! It had been graffitied and was in pretty poor shape, screws sticking out through the fibreglass shell and was missing all the electronics. (the ride was named Lily after the grafitied name across the top) Definitely wasn't safe as a kids ride so I had to make it "safer", even had a rusty screw slice my hand open when I was unloading it from my ute. Funnily enough, when I first got the ride, I did not fit inside.

The ride sat in my garage for about 2 months while I was trying to find an engine. I was originally bidding on a wrecked MT07 at the auctions. Luckily I lost because the next day a mate sent me a listing for a wrecked MT09, the big brother of the MT07. This is where the build took off, not progress wise, but idea wise. It has really become a build of "that's cool, why not". It was already going to be a cool build but why not go the extra mile to make it great. Around this time I also decided to go after the world record, which currently stands at 163.12km/h and held by a Postman Pat Van ride. To this day I haven't found any proof that the post van was still coin operated, which is why I like to say Lily is the fastest coin operated ride.

Now that I had the parts the build could finally start. I taught myself to weld, did a bit of practice and started welding the frame. It wasn’t perfect but it hasn’t fallen apart yet, but I have gone back ground out the bad welds and fixed it up since I’ve become a bit better. I managed to find a cheap go kart for sale to get axles and wheels from. I used the whole front end off that go-kart so I didn't mess up any of those important steering angles. 

From some research I’d done and videos I’d seen on go-karts with street bike engines, after 100 horsepower the tyres weren’t even close to holding that much power. I didn’t want to swap for a bigger wheel so I decided to add another axle. I am trying to break a record here, plus it's cool, not many 6x4 vehicles around, especially go-karts. 

A lot of “eyeballing” happened when I was making the engine mounts. I propped up the engine using some scrap metal and shimmed it using old grinder cutting discs. Gave it a good eyeball and welded it in place. And it ended up being pretty damn close to square. 

Now time to make it look the part. I cut up the old coin ride to fit it onto the frame. One thing I had not anticipated was how much of the back had to be cut out to fit over the rear braces. A big old hole which let a lot of heat into the cab, it gets quite warm in there now. I originally never fit inside the ride meant for kids but after cutting out some internal walls I could, with difficulty. Looking back I can’t believe I could fit in through the original door, glad I made the gull wing style door which used part of the roof.

The first idea I had for the pedals was to mount them on the floor. Which would have been about 10 cm in front of my butt while sitting down. I would have had to drive it in a squat, impossible, try it yourself, squat down and see if you can move your feet to use pedals. Lucky enough I worked out I could put my feet up into the nose of the ride, which is where the pedals now are. But it still wasn’t perfect. I had only mocked it up while wearing my good old safety boots aka thongs. The pedals were too close together and i didn’t realise until the first drive when i wore shoes, so the first drive i did barefoot. 

Not much planning happened for this build, so I had to rely on my great decision making. Which was not great. Made a lot of mistakes, which I've had to fix. But I’ve learned a lot from this build, not only building skills but also planning and research. And hopefully this should make my future builds even better

 

Now I had the body, frame and engine mounted, it was time to get it running. I was able to drop on the stock wiring harness. Next was probably the 2nd biggest mistake of the whole build and could have ended right here, the fuel tank. I decided to use a small 5L plastic jerry can i had laying around. I was using the stock fuel pump, an in tank fuel pump which bolted into the bottom of the tank. I used some fuel resistant liquid gasket to seal it in, since I didn't have the original rubber gasket. Not a great idea. Turns out fuel resistant is fuel proof, pretty much nothing sticks to the plastic jerry cans are made form (HDPE). I ended up with fuel leaking everywhere, almost a litre leaked out, but I was too excited. So I turned the jerry can fuel tank sideways so the leak wasn’t as bad, but it was still leaking. So with fuel leaking all over the engine, I started it up. It ran nice so I gave it a couple of revs. It only had the headers, which route under the engine, and it spat some pretty big flames from them. Very Very lucky it didn’t catch on fire

 

Work slowly kept going over the next year or so. Got a proper fuel tank without “leaks”. Built a coin mechanism to start up the engine. Pulled apart a tiny desktop vending machine that accepted 10 cent coins. And glued a cam to press the starter button. And it is the only way to start the engine. 

 

It was finally time to take it for a drive. But to test it I just wanted to make sure it would actually move. Had the fire extinguisher handy, for safety. Got in it, ready to go, started it  up. Let off the clutch a little, stalled it. Tried again. Let off the clutch a little and gave it some throttle this time. To be honest I’m not quite sure what happened, but I panicked a bit, maybe my right foot got stuck a bit as the pedals were too close, and I wasn’t used to having the clutch on the shifter. So it took off, spun the tyres, launched forward, slammed into the garage door, almost hit the dog. Took a second to realise what had happened and it continued spinning the tyres. It also didn’t have brakes, So I’m lucky the go-kart was in the middle of the garage and hit the divider between the two doors. And I didn't go out the open door, roll down the long steep driveway and into the front window of the house across the street. 

 

After I knew it was able to drive, I took it out somewhere safe to drive. Still didn’t have working brakes, but why not. Went pretty well, was excited to finally be able to drive it. And picked up on some issues to fix. The steering wheel was in a bad spot and was too big. I had to drive it with my arms crossed But the rest of it went well except when a wheel almost fell off. Turns out normal go-karts aren’t meant for over 120 horsepower. 

 

Since then I’ve spent many hours fixing dodgy things I'd done from the start, like the fuel tank. I had bought a proper aluminium fuel tank, but still did the dodgy on it. Used some liquid gasket to seal it up. At least this time i got the proper stuff, it didn’t leak this time. But after leaving it to sit for over a year it went bad and started to clog up the fuel filter. Which caused a lot of drama down the road. Cutting test sessions short and the fuel pump finally gave up on the dyno. I have now put in an external fuel pump, decided to weld it up instead of using sealant. 

 

Another dodgy thing I made was the shifter. I had originally kept the shift rod design, but since the shifter was located in the cabin, it had to be long. It was not great, the shifting felt spongy, and you had to slam to get into the next gear. Easy solution, Pneumatics. Designing it, not easy. The first bit of research I did was for this. Uses a 5 position, 3 way, normally open solenoid to control a small pneumatic cylinder that does all the hard work. Now with a press of a button I can change both up and down gears. But a button wasn’t gonna cut it, I needed paddle shifters, but where was I going to mount them? On a carbon fibre F1 style steering wheel of course, which is on a quick release, makes it a lot easier to get in and out.

 

 But pneumatics need a compressed gas to be able to operate, and I didn't want to mount a huge air compressor on board. I could have used CO2 but if i was going to have a bottle on board it was going to be nitours. I use the nitrous to run the shifter and of course, POWAH BABY!!! Just a little 30 shot for fun. 

 

Now with the build almost finished, the engine running well, the body work will be finished soon. I have to find somewhere to break a record. Unfortunately the go-kart isn’t like anything else. I can’t take it to any street car track events, it's not a race car, and its technically not a go-kart either. And most tracks don’t think it's an open-wheel prototype car, they keep calling it something called a death trap. So the biggest challenge of the whole build is to find somewhere to drive it.