This is my first post so let me introduce myself.
Hello fellow minibike enthusiasts my name is Clayton but everyone just calls me Ranger, its a nickname I got when I was growing up. I'm 19 and live in greater Houston area in Texas.
Anyway the minibike...
10 years ago:
I acquired an old minibike from a guy who lived in my area. It was an old rusted POS with a bad motor. My dad took off the old Tecumseh motor and put on a 2hp briggs motor from and edger. My dad made a rudimentary "idler pulley tightening a belt" clutch which worked alright. It was a good little minibike for when I was nine or ten years old. It would only go about 12mph and since I already had a go cart that would do 50mph the minibike didn't get ridden much. Overtime it was put up and forgotten about.
Present time:
One of the new guys at work rode up on his little Yamaha Vino 125cc motor scooter. That got me interested in my minibike again so I dug it out of storage and proceeded to get it running again. Throughout the years the motor had been taken off and used for another project so all I had was a rolling chassis. Luckily about 3 months prior a guy who lived in my neighborhood threw out a tiller with a 5 hp Briggs on it. I had already took off the motor and got it running like a top.
The motor was to big for the frame, the only way it would fit is if I took off the carb and gas tank. I also had a newer briggs 5.5 OHV motor that would fit but the crankshaft had a gear cut on it to run a gear reduction setup so that wouldn't work. I started thinking how I could get parts from one motor to make the other motor work on the frame. The 5.5 ohv motor had a traditional float style carb that would vs the 5hp pulsa jet gas tank and carb crap. Since the motors were only 1 cubic inch displacement difference I figured that the 5.5 ohv carb would work just fine on the old flat head, I just needed a way to mount the carb to the motor.
After pondering the thought for a while I decided to build an intake manifold from scratch, using nothing but 1/2" schedule 40 black iron pipe and some thick washers to make the flanges for the carb and engine. I built the intake manifold in about a week. It consists of an angled piece of pipe coming down to a 90 degree elbow to which the carb mounts to. The inside of the manifold is polished to some extent, I just got rid of the big stuff and made everything a smooth transition.
I put the intake on, bolted the carb up, put on a muffler, after a few minutes it fired right up. :thumbsup: I thought to myself, good I have a running motor now I just need everything else. :wink:
I'm somewhat of a hoarder, I have learned to not throw anything away that you think you might need later on. That paid off. 10 years ago, the old tecumseh motor had a basic cvt setup. I kept the drive pulley off the motor and held on to it just in case I ever needed it. Turns out after a little cleaning it worked just fine, better still it had the right shaft diameter size to fit the briggs. The driven pulley that gets smaller I left on the minibike since I first got it, it supposed to get smaller but being that this minibike is 30+ years old it seized up and didn't move. I used it anyway though.
Once I had all the parts I cobbled everything together for a test to make sure this would be work my effort cleaning and painting. I robbed throttle and brake cables from lawnmowers and used a 1 gallon gas tank from a snapper lawnmower. I held it to the frame with a piece of rope and bungee cord.
It works! It was incredibly crude and ugly but it worked. Since the driven pulley was seized and didn't move it limited my speed to 25 mph flat out, however the amount of torque this thing had was insane. Sadly I don't have a picture of it in this state, however I do have a video that I'm trying to upload to youtube if youtube would cooperate.
I rode it around in its test phase for a while tuning it and getting everything working properly before I decided to take it apart. However fate stepped it and made me take it apart. While I was riding it home the motor began to make a horrible rattling noise. I immediately shut off the motor to prevent more damage and had to push the bike home. Luckily I was only about a 1/2 mile from, I had just make a 4 mile trip in the minibike and was coming home. What happened was when I rebuilt the motor, I say rebuilt I took it all apart cleaned it and put it back together. Anyways I didn't torque the connecting rod properly and forgot to bend over the little metal tabs that keep the bolts from coming loose. They came loose about an 1/8 of and inch so there was a lot of play in the bearings :laugh: Only damage was to the rod, oil dipper, and to the block where the dipper hit the bottom. This time when I put the motor back together I put in a new rod, rings, and seals.
Now it was time for full restoration of the minibike, I had painted it black and gold 10 years ago and thought that was cool then. I sandblasted all the parts, painted the bottom of the fenders and frame with POR 15. I painted the frame and motor black. I had a custom paint mixed for the fenders, handlebars, motor recoil and wheels. Its DuPont Pepper grey metallic, the same color as the mustang in Gone in 60 seconds. Also put some racing stripes on the fenders and motor recoil.
OK that's enough typing for now. Only other thing I will add is that I got rid of the half working CVT setup that would only allow me to to 25 max to a centrifugal clutch from my old go cart that enables me to do 36 mph. It can go faster but I need a tachometer to make sure I don't over rev the motor and do more to the rod than just loosen the bolts.
My plan was to post pictures here and talk about specific parts on the minibike however neither photobucket nor the forum gallery will let me upload pics right now. I don't want to lose everything I have just typed so will post it and ad pictures later.
Hello fellow minibike enthusiasts my name is Clayton but everyone just calls me Ranger, its a nickname I got when I was growing up. I'm 19 and live in greater Houston area in Texas.
Anyway the minibike...
10 years ago:
I acquired an old minibike from a guy who lived in my area. It was an old rusted POS with a bad motor. My dad took off the old Tecumseh motor and put on a 2hp briggs motor from and edger. My dad made a rudimentary "idler pulley tightening a belt" clutch which worked alright. It was a good little minibike for when I was nine or ten years old. It would only go about 12mph and since I already had a go cart that would do 50mph the minibike didn't get ridden much. Overtime it was put up and forgotten about.
Present time:
One of the new guys at work rode up on his little Yamaha Vino 125cc motor scooter. That got me interested in my minibike again so I dug it out of storage and proceeded to get it running again. Throughout the years the motor had been taken off and used for another project so all I had was a rolling chassis. Luckily about 3 months prior a guy who lived in my neighborhood threw out a tiller with a 5 hp Briggs on it. I had already took off the motor and got it running like a top.
The motor was to big for the frame, the only way it would fit is if I took off the carb and gas tank. I also had a newer briggs 5.5 OHV motor that would fit but the crankshaft had a gear cut on it to run a gear reduction setup so that wouldn't work. I started thinking how I could get parts from one motor to make the other motor work on the frame. The 5.5 ohv motor had a traditional float style carb that would vs the 5hp pulsa jet gas tank and carb crap. Since the motors were only 1 cubic inch displacement difference I figured that the 5.5 ohv carb would work just fine on the old flat head, I just needed a way to mount the carb to the motor.
After pondering the thought for a while I decided to build an intake manifold from scratch, using nothing but 1/2" schedule 40 black iron pipe and some thick washers to make the flanges for the carb and engine. I built the intake manifold in about a week. It consists of an angled piece of pipe coming down to a 90 degree elbow to which the carb mounts to. The inside of the manifold is polished to some extent, I just got rid of the big stuff and made everything a smooth transition.
I put the intake on, bolted the carb up, put on a muffler, after a few minutes it fired right up. :thumbsup: I thought to myself, good I have a running motor now I just need everything else. :wink:
I'm somewhat of a hoarder, I have learned to not throw anything away that you think you might need later on. That paid off. 10 years ago, the old tecumseh motor had a basic cvt setup. I kept the drive pulley off the motor and held on to it just in case I ever needed it. Turns out after a little cleaning it worked just fine, better still it had the right shaft diameter size to fit the briggs. The driven pulley that gets smaller I left on the minibike since I first got it, it supposed to get smaller but being that this minibike is 30+ years old it seized up and didn't move. I used it anyway though.
Once I had all the parts I cobbled everything together for a test to make sure this would be work my effort cleaning and painting. I robbed throttle and brake cables from lawnmowers and used a 1 gallon gas tank from a snapper lawnmower. I held it to the frame with a piece of rope and bungee cord.
It works! It was incredibly crude and ugly but it worked. Since the driven pulley was seized and didn't move it limited my speed to 25 mph flat out, however the amount of torque this thing had was insane. Sadly I don't have a picture of it in this state, however I do have a video that I'm trying to upload to youtube if youtube would cooperate.
I rode it around in its test phase for a while tuning it and getting everything working properly before I decided to take it apart. However fate stepped it and made me take it apart. While I was riding it home the motor began to make a horrible rattling noise. I immediately shut off the motor to prevent more damage and had to push the bike home. Luckily I was only about a 1/2 mile from, I had just make a 4 mile trip in the minibike and was coming home. What happened was when I rebuilt the motor, I say rebuilt I took it all apart cleaned it and put it back together. Anyways I didn't torque the connecting rod properly and forgot to bend over the little metal tabs that keep the bolts from coming loose. They came loose about an 1/8 of and inch so there was a lot of play in the bearings :laugh: Only damage was to the rod, oil dipper, and to the block where the dipper hit the bottom. This time when I put the motor back together I put in a new rod, rings, and seals.
Now it was time for full restoration of the minibike, I had painted it black and gold 10 years ago and thought that was cool then. I sandblasted all the parts, painted the bottom of the fenders and frame with POR 15. I painted the frame and motor black. I had a custom paint mixed for the fenders, handlebars, motor recoil and wheels. Its DuPont Pepper grey metallic, the same color as the mustang in Gone in 60 seconds. Also put some racing stripes on the fenders and motor recoil.
OK that's enough typing for now. Only other thing I will add is that I got rid of the half working CVT setup that would only allow me to to 25 max to a centrifugal clutch from my old go cart that enables me to do 36 mph. It can go faster but I need a tachometer to make sure I don't over rev the motor and do more to the rod than just loosen the bolts.
My plan was to post pictures here and talk about specific parts on the minibike however neither photobucket nor the forum gallery will let me upload pics right now. I don't want to lose everything I have just typed so will post it and ad pictures later.
