How To Build A Minibike

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When Tim rides, abides by this code: Think safety, respect nature, and always wear helmet. Young Johnson brought together components from several sources to assemble his $60 minibike.

MOTHER’S CHILDREN: This 13-year-old built a scooter for only $60!

MOTHER EARTH NEWS feels strongly that youths can be creative “Doers,”working toward more ecological and self-reliant lifestyles . . . whether their tasks be raising chickens on a farm or maintaining rooftop container gardens in the city. To support the endeavors of our often overlooked “underage” citizens, we’re glad to publish well-written articles from younger children and teenagers concerning projects they’ve undertaken. However, we recommend that all young authors query (that is, send us a letter telling about the story they’d like to do) before writing a full article. Address inquiries to Mother’s Children, MOTHER EARTH NEWS, Hendersonville, NC.

How To Build A Minibike

Like many other kids, I wanted a minibike I could scoot around on. But most new minibikes cost from $260 to $450. I couldn’t afford that — I only had $70!

One day while I was working with my dad, I got the idea of making my own minibike. I told my dad. He said I could try, but he doubted I could really do it.

That didn’t stop me. The first thing I did was to start looking for a used engine with a side shaft. I tried hardware stores and also shops that repaired lawn mowers and small engines. The best-priced engine I found was a 3-horsepower Tecumseh with a 5/8 inch side shaft. It cost me $35.

Then I started the hard job — looking for a minibike frame. After trying junkyards and other places, I finally found one in a lawn mower repair shop. It had a size #35 chain, brakes, tires, chain sprocket, throttle grip, and throttle cable . . . and it only cost me $5!

There was just one thing left that I needed: a centrifugal clutch (that’s the kind of automatic clutch that engages when you accelerate the engine). It had to have the same size hole as my engine shaft, as well as gear teeth that would fit my chain. So once again I began looking in shops. In a hardware store, I found a new centrifugal clutch that would do. It cost me $20.

Now I had the main parts for my minibike, and I’d spent only $60. Then came the fun part — putting them all together!

First I bolted the engine to the frame with strong bolts, nuts, and lock washers. Next, I put the centrifugal clutch on the engine shaft. To do this, I first lined up the key slot on the shaft with the key on the clutch. (I put the clutch on so its chain sprocket was on the inside.) I tightened the key in place with an Allen wrench. Once that was done, I hooked the chain up to the sprocket on the clutch and to the other sprocket on the minibike.

The only job left was to hook up the throttle and throttle cable. I put the cable end that had a ball on it into the throttle grip on the minibike’s right handlebar. Then I slid the other cable end into the clamp on the side of the engine and through the hole in the metal bar that controls the engine speed.

To hold the wire end in place, I made a wire swivel stop (you could buy one at a hardware store if you wanted to). I drilled a hole through a nut, slid the wire through the hole, and then — once I had the wire as tight as I wanted it — screwed the bolt on the nut to hold everything in place.

I also hooked a spring to the engine speed bar and another part of the engine. That way, whenever I let go of the throttle, the engine bar gets pulled back to its idling position.

That’s all it takes to make a minibike. I’ve had a lot of fun with mine. Remember, if you make one, to be careful when you ride it — minibikes can go 25 miles an hour! Always wear a helmet when you ride, and always stay off public roads and untracked property.

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