Maxi Mini: 1970 Heathkit GT-18 Boonie-Bike

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It sounds like this rare 1970 Heathkit GT-18 Boonie-Bike has been in storage since the early-1970s and it has zero hours on it, it’s basically never been used. It can be found here on eBay with bids of over $3,000 as I write this and, believe it or not, the reserve isn’t met! It’s located in Novi, Michigan.

The first photo shows the rare front ski option which was $16.95 and there can’t be many of them left today in any condition, but in like-new condition, this is probably the only one. Heathkit started out in the late-1920s selling light aircraft kits and after WWII they started selling surplus electronic kits that customers could put together to make various things like oscilloscopes. In 1968, they started offering mini bikes. The information that I found says that the GT-18 Boonie-Bike was only made in 1968 and 1969 so this could be a case where one was purchased and squirreled away, which is what it sounds like, although they have the VIN listed as a 1970.

The seller says that this Boonie-Bike was donated to a school in the early-70s and put into storage for years. They say that it has zero hours on it and is about as close to new condition as possible. I can see some chipped or worn paint on some of the edges but overall, yeah, it looks great! A very nice original is usually better than a restored one, and that goes for anything. That’s just my opinion, though.

The Boonie-Bike was meant to be an all-terrain, year-round mini bike, hence the front ski attachment. This one also has the optional battery charger which would have added $6.95 to the price. It also has the horn and lights kit which was $29.95 extra. I believe that the only other option would have been a spark-arresting muffler at $9.95. The condition of this bike is amazing, at least in appearance.

There are no engine-specific photos but you can see the 5-hp Briggs & Stratton in a few of the photos and I’m not really sure about the operating condition but I’m assuming that it works great and they were good for speeds up to 30 mph. They seller says that it is or was minimally ridden for demonstration reasons only. It has a unique 2-speed centrifugal clutch which fed to a jackshaft. There are two sets of chains running to the jackshaft and two gears in the clutch, a fairly complicated system for a mini bike in the late-1960s. Unfortunately, you can’t shift while you’re moving or it’ll snap the jackshaft spring and you’ll be stuck in 1st gear going 15 mph at the most. I know that there are vintage mini bike fanatics out there, any thoughts on this Heathkit GT-18 Boonie-Bike?


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  1. Ken Carney

    I knew Heathkit made CB radios, but never a minibike! It looks very over
    engineered like their radios too. Any thing you bought from them was top
    notch through and through. Too bad
    they can’t make decent products like
    this today.

    Like 10
  2. Dan

    It’s neat, seems reasonably priced, and is pretty close to me. But since I couldn’t legally use it as a commuter, it’s a pass for me.

    Like 1
  3. BobinBexley Bob in BexleyMember

    Comes with ‘Twin Peaks’ flooring ! Can you hear the music ???

    Like 1
  4. HoA Rube GoldbergMember

    Yeah, Heathkit was big, into all kinds of stuff, a friend had a Heathkit weather station he built. I had seen these before, in my dirt bike days, there was always some kid with one, the operating controls are pretty straight forward, I had a friend with a Rupp minibike that had a 2 speed like that. It worked rather well. Fun to see this stuff, when simple was good enough.

    Like 9
  5. jmolsnMember

    Wow! Talk about memories!! My Dad bought me one when I was 10 or 11. Have many memories of tearing around the property. We also built many electronic projects over the years.

    Like 7
  6. Robert E Pietrafesa

    Bought one of these in 1968 – with money saved from a paper route. Ran like the wind and the 2 speed was unique!

    Like 1
  7. geomechs geomechsMember

    I don’t know where you find these, Scotty, but your features are unique. I saw a lot of variations on minibikes but this one escaped me. Looks like something fun to ride just the same. It reminds me of the Fox Trailbug we had many years ago. If I still had a lot at the lake resort I would look a little closer at something like this.

    Like 3
  8. rod444

    My dad built a Heathkit stereo and we had “hifi” sound when everyone was still thinking “monaural” was good enough. Very old school indeed.

    I lusted after this minibike for years as a kid. Wanted one so bad I could taste it. My folks always said ‘no’. And then what happens? As soon as I turned 16, my father goes and buys a sport bike. At least he let me ride it.

    Like 2
  9. Cattoo CattooMember

    I recall something a bit larger as being advertised in the back of magazines such as popular mechanics, to haul out game after the hunt was over. Think I may have even been front wheel drive via a chain drive.

    Like 1
    • Scotty GilbertsonAuthor

      Cattoo, a two-wheel-drive Rokon maybe?

      Like 1
  10. Phinias

    Heathkit had a LOT of great kits. My dad built an incredible stereo system designed and sold by Heathkit. It was a very good system back in the day. He could make all the windows rattle in the house when the volume was cranked up!
    I built a shortwave kit of theirs as a kid. It was great stuff!

    Like 0
  11. Beel

    I had one of these, too. Dad bought it for me and we assembled it together. Living in northern Ohio, we also had the front ski. Didn’t have the light kit. It was a great bike and much less expensive than the neighbor kids’ Honda bikes. I eventually pulled the engine to put on my go-kart and never rode it after that.

    Like 0
  12. Jim Norton

    This is a older restore . None of the cables are correct. The throttle handle is not correct should be chrome. The motor, fenders ect all white parts have been repainted except the wheels were not painted they do not match the much whiter paint. I have seen a lot of boonies and never saw one that has been crashed hard enough to bend both foot pegs back so it has been crashed hard on both sides. The rubber hand grips are not correct. The brake light switch is not correct. If i could post a picture of mine you would see a nice one.

    Like 3
  13. treg forsyth

    The frame sure looks like a Bonanza, no Bonanza tag or plate where it would attach bettween the front forks, I have two Bonanzas, and the prices are climbing just like all that cool stuff that we had as kids.

    Like 0
    • craig

      treg, heathkit was a benton harbor, michigan company they made 2 models this boonie bike & the hilltopper. the bonanza company was from san hose california i think they had 8 models. and you’re correct on prices, i am responding to you in july of 22 just one set of bonanza mag wheels bring 2-400 bucks depending on condition, good day eh

      Like 0
  14. Ed

    An Ohio resident, I found one in a remote area of the state up by Lake Erie. A friend and I restored it, but painted it in bright red urethane. It only had the higher gear, but ran like the wind. I rode it everywhere, even on the streets of my rural township (the cops didn’t care.) Sadly, several friends just had to ride it; many laid it down. Eventually, I was hit while riding it by a distracted driver who blew through a stop sign in her SUV. I sued, and the proceeds paid for the bike and all the restoration costs. I later donated it to my brother, who completely ruined it. Big fun.

    Like 0
  15. Kevin Faller

    We had all kinds of Heathkit stuff. TV, Stereo, Shortwave receiver, Vacuum tube voltmeter, Heath’s version of Pong – with 3 color options!!. I also had the Heathkit Boonie bike. One winter, someone broke into our shed and stole it. I was so angry! The shortwave and VTVM are still sitting on a shelf in my mom’s basement.

    Like 0
  16. Lee

    Bought one in 1970 first mini bike , was a blast in the snow, drive chains were to small I think #30 always breaking and that 2 speed was a pain would let friends ride it and they would forget to stop to shift breaking the spring in the jack shaft mechanism.Replaced a few of them, Had to assemble it when I got it . It’s was fun went through sand good with that big tire in back.cant believe there are still some around!

    Like 0
  17. Ed

    I switched out the 5 hp Briggs with a 10 hp, disabled and removed the two speed gearing, and added a torque converter. The bike was perfect for ADV riding as well as street. Plenty of climbing power and it flew on the streets. The extra speed called for a front braking system, but I called a halt to this, as the project was becoming quite expensive. It was remarkably stable at speed, but the lack of suspension made it prohibitively dangerous.

    Like 0
  18. BrokeDog

    Totally ran the wheels off our Boonie bikes! Wore them out!

    Like 0
  19. Rj

    A friend of mine had one of these in that era. For some inexplicable reason, he was driving down an alley and he blindly shot across a 30 mph road and he ran directly into a passing car. He was unhurt and can’t remember how the boonie bike made out. A teen neighbor said if he “would have hit my car, I’d back up and run him over.”

    Like 0
  20. BrokeDog

    We were in peanut country, with me and a cousin on my bike, and my brother and another cousin on his. We were flying down a sandy road when my brother decided to change lanes … and wiped out in the sand! We smashed into them at around 25 mph. No one hurt (except the forks on my front wheel). Lucky!

    Like 0
  21. Ed

    I had one when I was kid. It was sold in kit form.Low gear was a hill climbing monster. The bike was tough as nails and it survived many spills.
    We had hours of fun on ours from the mountains to the beach. I wish the still made them.

    Like 0
  22. Brian Scott

    We had a Boonie-Bikeback in the day (with the ski) and it was the greatest! I remember winters in northern Indiana at the frozen lake surrounded by snow covered fields and woods. Talking with a friend at work today and reminiscing when I remembered 40 or so years ago. Long story short, I came home and googled HeathKit. It’s true that things were “more wonderfuller” back then.
    The only problem was having to share it with 5 brothers and sisters, my dad who was a kid-just bigger and the neighbor kids all wanting to take their turn.

    Like 0
  23. Rod S

    We had one when I was growing up. It was always breaking down and didn’t get ridden much.

    Like 0
    • BrokeDog

      That was the good thing about them … they were very easy to fix (even for a guy that was not very mechanically inclined, at the time). I was always doing something to keep ours running. They were really the only half-way decent things we ever got outta my sorry, no good a-h*le of a step-(refuse to even call him a d*d)!

      Like 0

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