Thread: mini bike frame

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You are right, the footpegs should be up front but that engine is too large and took up the spot where your feet would lay comfortably. So the only alternative was drag bike style, behind the engine. I think wheelie bars would help, maybe that is next...........after all, the Billetproof drags are coming up in October and they have a minibike class.

Don

Here is what mine looked like when I bought it. Someone had cut off the engine mounting plate, so I had to redo my frame and straighten it as it was bent from years of abuse.

Thanks for the help and ideas. I found out that its not a Rupp "continental" but its actually a Rupp "Digger" Same bike but has a gas tank mounted on top.


I sent a wire brush down the pipes , actually a home made brush made with long lengths of welding wire with the ends bent about 5 feet long hooked to a drill. Very dangerous but it seemed to work. When I flipped the frame over I did not see any big rust particles come out (good sign) , but there was some black fine powder.

Seeing the bulge in tube it makes since that water got into it and froze. Glad that it is from water freezing and not just rusting out which would be worse,IMO. I spent a few minutes late last night massaging the bulge with a brass hammer to try and lay it down evenly. The metal is still pretty tuff but its moving, so I think the metal in these areas is still pretty good. Gonna try and get it weld up today , I will get some pics.

As silly as it sounds, building one of these is a lot more fun than building a car, I really enjoyed restoring mine. They are so simple and not very expensive to restore. I have just about $ 400 in mine, including the on sale HF motor at $ 99.00. The only mistake I made was thinking that more hp would be better..........should have put nothing bigger than 5 hp on it. A 5 would have also been physically smaller and left more room for my legs and feet.

I might fab up some wheelie bars and give it another try.

Don

Built one of these for my boys some 40+ years ago.. Wife got peed off cause I did it. The boys loved it then she got on it to go down the street a cop stoped her hahaha. He told her she should know better.

Originally Posted by cffisher

Built one of these for my boys some 40+ years ago.. Wife got peed off cause I did it. The boys loved it then she got on it to go down the street a cop stoped her hahaha. He told her she should know better.

.........kharma......

I have a TC 100 frame, have a vintage B&S 3.5hp ( model 5S 1953 serial number ) engine that I want to rebuild for it, but I'v wanted to for the last 10 years. just no time

I got the bulges tapped down and welded up. The straight one was no problem the one on the bend was a little harder, but I think they will do. Luckily , and what has probably save the frame all these years is the use of shocks on the frame.
Time to start with painting the frame. Looks like it has enamel paint on it.

Before welding


This one was a little harder due to the bend and thinner material at the bend. I had to stick a screwdriver in the slot because the metal in the middle of the crack wanted to fall below the other edge before it got into position, and I ended up with a gap. I tacked the crack up and added more material in the area.


Welded up.

Nice job on the cracks, frame looks great!!!!

Thanks Dave.

Yep coming along very nicely! Great job on fixing the cracks.

Steve is right, you will be fine with those welded like that. BTW, Northern Tool carries a few mini bike and go kart parts like tires, wheels, sprockets, clutches, etc. They have a section devoted to them and the prices aren't horrible.

Check online and in the store at Harbor Freight for an engine. They go on sale often and usually in the $ 99.00 range. I looked at their website for you and the only one I saw was the 99cc one shown below. From what it says, this is a replacement for a 3hp engine, and would be about right, especially for a kid using it.

The one I bought for $99 was a steal and is really a very good engine.........fires up on one pull and runs smoothly. Just a bit more hp than I needed.

Don

Thanks Don, I looked briefly at harbor freight over the week end and did not see that one. I will look a little more today, it was late and I just did a quick search. I would like to find a older motor that is rebuildable but will do the Harbor Freight deal also.
Has any tried this for rust?

I bought a bottle about a year ago to try out and never got around to it until now. The rust was 100% removed in 12 hours from all the small parts. I am happy with the stuff , will have to look into it a little more.
I was able to disassemble and clean up the shocks with the rust remover also and it looks like I will be able to use them, so thats a plus.
I am still not sure how to paint this thing. I could buy a cheap one time sprayer from harbor freight to paint but I want to paint to last. What it has on it now seems to be enamel. Would powder coating be better then anything I can spray?

Powder coat seems to be the most durable finish. It's thick and durable, where if you scratch it, you'd probably not penetrate to metal, where as spray on you'd need lots of top coats to achieve the same level of thickness. Either would be fine, but if powder coating doesn't cost too much, it will hold up better to anything your kids throw at it!

At $ 99 on sale, you can't beat the HF price on motors. I first bought a 5 hp at a swap meet for $ 50 and had to buy a carb kit and other small stuff for another $ 40 and it never ran right, so I sold it and opted for the brand new one from HF. I don't know how they sell them for that money, they are really not bad at all and have a good warranty.

As for paint, I bought a quart of yellow Rustoleum paint and sprayed mine over epoxy primer. It took a little longer to cure than the 2 part paints we usually use, but in a few days it was as hard as a rock.

Don

Yep, you cant beat 99 dollars for a new engine. Ill have to go up to the store to see if they have any in store specials. I checked them out and the websites lowest price is 140 , not to bad for a engine I will use just to fart around. I checked out Northern tool and supply also but their prices are way to high and they dont have anything really. I did find some bearings for the handle bars and paid 11 dollars for them , got home and check online to find the same brand and parts for 1.50 each. My Plans have changed though , the mini bike will now be mine,lol. I will have time to look for original parts since the kids wont be using it. I will mainly use it at the race track to get to the staging lanes, or swap meets and to haul ars to the the blue house.
The guy I got the mini bike frame had a go cart I could not pass up and I will use this for the kids. 150 for a Manco Dingo go cart minus the engine but does have the torque converter. It looks like this, but not as pretty