My MiniMax project

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I rarely think about the cost of these projects when I start out. This one was expensive... should probably wrap it up and call it a day. Or maybe put that turbo on it... we'll see : )

Good luck with your project!
 
While the minibike project's end is in sight(just little stuff now like electronics and making it look pretty), I've already got another I'm working on for a friend. We thought it would be pretty sick to mount the old 6.5hp motor on what used to be a wal-mart electric scooter. The motor had burnt out a while ago and it was just sitting in his garage. So far that's been gutted of all it's electronics and both wheels. Made some engine brackets out of angle iron to mount the motor just behind the rear wheel. Now the tough part(that I'm still not totally sure how to do) is mount a #40 sprocket onto the plastic rim. I cut the original #25 chain sprocket off(was press-fitted onto the rim), which now in retrospect wasn't the best idea- Think I could have just welded the new sprocket to the old one. The good news is that it's a solid rubber rear tire, so I can drill through the rim with no ill effect. Get a couple long lag bolts, drill a square pattern, effectively creating a square pattern of studs in the rim. Pop some holes in the sprocket, get the spacing right to line up with the motor, and should be good to go.

Already got a throttle cable and twist-grip, so once the sprocket gets mounted it's home free.

The scary thing is that the back wheel is only 8" in diameter, I can only fit at most a 30T sprocket on it. The clutch has a 10T, giving only a total 1:3 reduction. Should put the top end near 40mph. On 8" wheels standing up, I imagine that will be pretty damn fast.
 
OK....almost done. Only thing left is I'm waiting on a custom made exhaust for it from Robertson's Kart Pipes. The snowblower exhaust shoots right onto the secondary clutch and it's getting gunked up with carbon so I had to do away with that.

The paint job was done on my own with rattle cans and some painter's tape. Honestly, it came out a lot better than I was expecting. Close inspection reveals a dribble here or there, but on the whole I think it looks good.

The Comet TAV-30 torque converter is worth it's weight in gold. Night and day difference from the centrifugal clutch and fixed ratio. So much more torque.

I added a little array of gauges...the speedo reads up to 100mph so I can accurately track mileage and speed all the way to top end of about 60 or so. The Tiny Tach shows minutes/hours run when the motor is off and switches to live RPM reading when it's running. Just has a small "antenna" wire that wraps around the plug wire to sense spark. And a small cluster that shows current voltage and ambient temperature.
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well boys here is the mini max... Stage 7 w/ a kerker (wheelies as long as you want it to) not good to wheelie more than an 1/8 mile because there's a dipper off the bottom of the crank on these(all splash).....The motor next to it is getting quite a bit of goodies. That will go in my mini chop project
 

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well boys here is the mini max... Stage 7 w/ a kerker (wheelies as long as you want it to) not good to wheelie more than an 1/8 mile because there's a dipper off the bottom of the crank on these(all splash).....The motor next to it is getting quite a bit of goodies. That will go in my mini chop project

Do those scoops work? LOL That thing is cool and it will wheelie forever. I know first hand. What's goin on with the other engine? I should have some work done to that 8 horse of mine.
 
Do those scoops work? LOL That thing is cool and it will wheelie forever. I know first hand. What's goin on with the other engine? I should have some work done to that 8 horse of mine.
I have a super high compression head that was milled .030. Also the chamber in the head was filled. Bought a billet aluminum rod and an aftermarket cam. The motor is a cast iron bore dual bearing block with magnatron ignition and a 12V Stator. I had it running and put my test light to the leads briefly and it almost melted the test light :biglaugh:
 
Gary, there's a shitload of OHV stuff out there. For the OHV's, a cam is a great upgrade. You already have a good exhaust which is the most restrictive part on the stockers....BTW i've driven Gary's mini chop and that thing screws !! If you keep you're feet up on the pegs from a slow roll and crack the throttle, it smokes that big 205 right off the back...Very stout :punk:
 
Gary, there's a shitload of OHV stuff out there. For the OHV's, a cam is a great upgrade. You already have a good exhaust which is the most restrictive part on the stockers....BTW i've driven Gary's mini chop and that thing screws !! If you keep you're feet up on the pegs from a slow roll and crack the throttle, it smokes that big 205 right off the back...Very stout :punk:

Been working on it a little. It told me the other day it needs that Chinese turbo.
 
John,

Remember Dave on my Chappy? that was a cool little ride. He'd wheelie that thing forever

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That looks like a pretty sweet mini...knew a few people here must have some mini-cycles to mess around with.

I thought about picking up a frame similar to Dr.n2o's...like a true "minibike" frame and working that up, but I decided to invest the money in my Baja instead and really do it up. I like the larger frame of the Baja bikes....you can actually ride it on trails and such without killing yourself, and mine now is very off-road capable. Mud, sand, hills...it's great. I actually prefer it to my friend's Kawi 125 dirt bike just due to the smaller size...more manueverable at slow speeds.

Good luck finding one of those Comet Torq-a-Verters now.....Comet went out of business this past fall and TAV2's are next to impossible to find new anymore(believe me, I called probably 2 dozen kart shops and nobody had stock left). There's some on eBay going for stupid high prices($300+). I've heard that a Chinese clone is on the way from a couple kart shops, so we'll see.

I'm really intrigued by that chinese turbo...for only like $300 it could be pretty kewl. But even stock this bike has more than adequate power, and I don't really want to mess with the motor too much in the interest of making it last a long time and be reliable.

My custom exhaust from Robertson's should arrive tomorrow. Had to ditch the goofy garbage-picked snowblower exhaust because it was crapping up the secondary with soot and it started sticking. He agreed that the stock mufflers are very restrictive in the interest of quiet operation, and his dyno testing(there's sheets on his website) show a good half-horsepower increase with one of his muffled exhausts over stock. A decent gain, considering it's 11hp to start with.
 
That looks like a pretty sweet mini...knew a few people here must have some mini-cycles to mess around with.

I thought about picking up a frame similar to Dr.n2o's...like a true "minibike" frame and working that up, but I decided to invest the money in my Baja instead and really do it up. I like the larger frame of the Baja bikes....you can actually ride it on trails and such without killing yourself, and mine now is very off-road capable. Mud, sand, hills...it's great. I actually prefer it to my friend's Kawi 125 dirt bike just due to the smaller size...more manueverable at slow speeds.

Good luck finding one of those Comet Torq-a-Verters now.....Comet went out of business this past fall and TAV2's are next to impossible to find new anymore(believe me, I called probably 2 dozen kart shops and nobody had stock left). There's some on eBay going for stupid high prices($300+). I've heard that a Chinese clone is on the way from a couple kart shops, so we'll see.

I'm really intrigued by that chinese turbo...for only like $300 it could be pretty kewl. But even stock this bike has more than adequate power, and I don't really want to mess with the motor too much in the interest of making it last a long time and be reliable.

My custom exhaust from Robertson's should arrive tomorrow. Had to ditch the goofy garbage-picked snowblower exhaust because it was crapping up the secondary with soot and it started sticking. He agreed that the stock mufflers are very restrictive in the interest of quiet operation, and his dyno testing(there's sheets on his website) show a good half-horsepower increase with one of his muffled exhausts over stock. A decent gain, considering it's 11hp to start with.

I remember when I was a kid (long time ago: ) I scored my first Rupp 5 HP with suspension. That thing was a hoot! banged me up a few times. Someday I'm gonna do another mini and try to keep it light with suspension. More or less like the one your working on. Keep up the good work!
 
Here is one that was at the car show last year. It beat out all the other bikes (mine, a ZX14, Busa, Harleys) for ppl's choice.
 

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I don't ride trails or anything with mine. I cruise that thing all over town. Rides like a dream. I get up @ 4;30 Sunday mornin and right when the sun cracks I go out for about an hour after a cup of coffee. There's a couple older dudes that always give me a thumbs up when I go rippin by their house. I have a robertson 3 stage that runs awesome but I took it off and am going to use that when I start the ol' mini chop. below are pics of the head for the mini chop
 

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