Ok guys, my name is Thomas and I'm here to talk about mini bikes. Lets get started.
While back, bought my girl a nice little doodle. It had been resprayed but it all worked pretty good except the engine would not idle cold. She got it as a surprise gift on her 21st birthday. We ride bikes to class together, well we used to. I recently resurrected an electric minibike I made back in high school and she was all kinds of jelly watching me not have to pedal. SO, that started me looking for something she could ride. Found this doodle, bought it off craigslist and stored it in a friends garage till her birthday. Here she is:
I liked the little guy and it was a great start for her to learn on. It was pretty weak tho and she couldn't really keep up with me on hills. So, I started looking around on you tube and such and such and decided I was going to put a bigger engine on it if I found one. Then, I get a call from my g/f one day asking me to come get here cause the doodle stranded her on the side of the road coming home from school in the rain. It was hilarious. SO, needless to say, it was really time to find a solution. Ran across a stupid awesome deal in my search for a cheap engine. I went to a local small engine/ mower shop and asked if he had any horizontal shaft engines that are in need of some work I could buy cheap. We looked through his junk yard but didn't find anything. We were headed back to the front of the store through his shop area and I saw a horizontal shaft engine and said, "what about that one". He had forgot he had it. It was a motor he had replaced on a baja heat or warrior under warranty since it was leaking. Anyway, it was literally bran new. He asked me for $60 and I said yes. This thing is so amazing. It starts first pull every time and idles like a dream.
So I set about installing it. Luckily since I am on a design team at my college I have access to a pretty nice machine shop 24-7. I took a clutch I found around the shop and modified it on the lathe to work on this engine. Welded up a little adapter and bolted the engine on. The wiring just plugged in as it is very similar to the doodle as they are both made by baja. Here is what it looked like right after I put it all together in less than 24hrs.
So, as you can see, the engine was way over to one side to accommodate the FREE clutch that couldn't be inverted to work with the sprocket on the inside. The clutch was literally the worst thing ever as it turns out. It was so harsh on engagement that it bent the engine plate and broke the welds on the frame that hold the foot peg bar to the frame. But overall, when the clutch wasn't killing the bike it lived on it all worked out pretty good. Then, one day my g/f got pulled over by the police on her way to class, haha. He asked her about the bike and how big the motor was. She kept her leg over the 200cc sticker and and played dumb. He told her it needed lights and a mirror. SO, since this bad ass engine had a generator on it we wired up a headlight and taillight with a brake switch. Added a sweet little mirror. A month or so later, I got pulled over. It was the same cop. He told me he pulled over my g/f. It was funny. We had removed the sticker and I tried to play dumb but he had had his own minibike growing up so he knew it was not 49cc. He said he didnt car though since it had a mirror and lights.
Then, me an my g/f split. She felt bad so she gave me the doodle, lol. We actually are happily back together nowadays but before we got back together I took a pretty decent spill on the ol'doodler. Broke the mirror, grips, and tore the bar that holds the foot pegs. SO, this combined with the unbearable clutch called for a full blown do-over. Really, I should have just pimped out the old motor, but I wanted to go big. This brings us up to speed with the new build on this doodle.
NOW, for the good stuff.
Original plan was to stuff the vanguard 16hp engine in the doodle with a BSA or Triumph pre-unit 4 speed tranny behind it. I bid on several gearboxes but they kept going well out of my price range. Found a Vanguard on eBay that was located in my hometown coincidentally so I pulled the trigger on it. Only problem is that it was a taper shaft. No problem, bought a nice 1" shaft crank from a vertical shaft mower vanguard. Its slightly longer than the version for the horizontal but is otherwise exactly the same I was pleased to find out. I bought it before I had torn the motor down so I was relieved to see that it was completely compatible.
New plan is to bolt a gtc tc2 1003 torque converter to it with a 18 tooth pinion and a 54 tooth rear sprocket. Should make for a 60mph doodle at 4000rpm with the 13" diameter street tires I'm going to be running.
All I have done so far is ordering all the parts and tearing the motor down tonight. After clean up I am going to put the new crank in and take out the governor, then bolt it all back together and test fire it. Here all some pics from tonight:
Donor Bike
Goal is to make it a real high performance bike. I'm running a 6.5 inch rim up front with a 110/50R6.5 treaded street tire and a stock rear rim with a 13" street tread tire on it with an upgraded rear caliper. All upgraded thick cable for the brakes. Should be pretty sweet. Ill keep you all updated.
While back, bought my girl a nice little doodle. It had been resprayed but it all worked pretty good except the engine would not idle cold. She got it as a surprise gift on her 21st birthday. We ride bikes to class together, well we used to. I recently resurrected an electric minibike I made back in high school and she was all kinds of jelly watching me not have to pedal. SO, that started me looking for something she could ride. Found this doodle, bought it off craigslist and stored it in a friends garage till her birthday. Here she is:
I liked the little guy and it was a great start for her to learn on. It was pretty weak tho and she couldn't really keep up with me on hills. So, I started looking around on you tube and such and such and decided I was going to put a bigger engine on it if I found one. Then, I get a call from my g/f one day asking me to come get here cause the doodle stranded her on the side of the road coming home from school in the rain. It was hilarious. SO, needless to say, it was really time to find a solution. Ran across a stupid awesome deal in my search for a cheap engine. I went to a local small engine/ mower shop and asked if he had any horizontal shaft engines that are in need of some work I could buy cheap. We looked through his junk yard but didn't find anything. We were headed back to the front of the store through his shop area and I saw a horizontal shaft engine and said, "what about that one". He had forgot he had it. It was a motor he had replaced on a baja heat or warrior under warranty since it was leaking. Anyway, it was literally bran new. He asked me for $60 and I said yes. This thing is so amazing. It starts first pull every time and idles like a dream.
So I set about installing it. Luckily since I am on a design team at my college I have access to a pretty nice machine shop 24-7. I took a clutch I found around the shop and modified it on the lathe to work on this engine. Welded up a little adapter and bolted the engine on. The wiring just plugged in as it is very similar to the doodle as they are both made by baja. Here is what it looked like right after I put it all together in less than 24hrs.
So, as you can see, the engine was way over to one side to accommodate the FREE clutch that couldn't be inverted to work with the sprocket on the inside. The clutch was literally the worst thing ever as it turns out. It was so harsh on engagement that it bent the engine plate and broke the welds on the frame that hold the foot peg bar to the frame. But overall, when the clutch wasn't killing the bike it lived on it all worked out pretty good. Then, one day my g/f got pulled over by the police on her way to class, haha. He asked her about the bike and how big the motor was. She kept her leg over the 200cc sticker and and played dumb. He told her it needed lights and a mirror. SO, since this bad ass engine had a generator on it we wired up a headlight and taillight with a brake switch. Added a sweet little mirror. A month or so later, I got pulled over. It was the same cop. He told me he pulled over my g/f. It was funny. We had removed the sticker and I tried to play dumb but he had had his own minibike growing up so he knew it was not 49cc. He said he didnt car though since it had a mirror and lights.
Then, me an my g/f split. She felt bad so she gave me the doodle, lol. We actually are happily back together nowadays but before we got back together I took a pretty decent spill on the ol'doodler. Broke the mirror, grips, and tore the bar that holds the foot pegs. SO, this combined with the unbearable clutch called for a full blown do-over. Really, I should have just pimped out the old motor, but I wanted to go big. This brings us up to speed with the new build on this doodle.
NOW, for the good stuff.
Original plan was to stuff the vanguard 16hp engine in the doodle with a BSA or Triumph pre-unit 4 speed tranny behind it. I bid on several gearboxes but they kept going well out of my price range. Found a Vanguard on eBay that was located in my hometown coincidentally so I pulled the trigger on it. Only problem is that it was a taper shaft. No problem, bought a nice 1" shaft crank from a vertical shaft mower vanguard. Its slightly longer than the version for the horizontal but is otherwise exactly the same I was pleased to find out. I bought it before I had torn the motor down so I was relieved to see that it was completely compatible.
New plan is to bolt a gtc tc2 1003 torque converter to it with a 18 tooth pinion and a 54 tooth rear sprocket. Should make for a 60mph doodle at 4000rpm with the 13" diameter street tires I'm going to be running.
All I have done so far is ordering all the parts and tearing the motor down tonight. After clean up I am going to put the new crank in and take out the governor, then bolt it all back together and test fire it. Here all some pics from tonight:
Donor Bike
Goal is to make it a real high performance bike. I'm running a 6.5 inch rim up front with a 110/50R6.5 treaded street tire and a stock rear rim with a 13" street tread tire on it with an upgraded rear caliper. All upgraded thick cable for the brakes. Should be pretty sweet. Ill keep you all updated.
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ut:, a 1" shaft, correct oil filter adapter, and a whole lot of work ahead of me. Here are the pics in order of how I took them ass I assembled the engine. Enjoy!
