Just won this on ebay. I am hoping it will look ok. I think it will, because those JR50's are really small.
Marvin Martian's Madwagon
- Thread starter marvin martian
- Start date
Here is what I have so far for mounting the seat. I don't know if I like it yet, but it's all I could come up with to mount the rear of the seat. I am worried about the frame bending eventually, I guess I will just have to keep an eye on it. I need to finish fitting it together, then tack it together with brass, then I will take it to my pipefitter buddy @ work so he can final weld it for me.
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Well, I finally figured out what Seca40 was speaking of earlier in this thread, when he talked about tire/chain clearance issues. (I am slow but I figure it out eventually) When I mocked up the engine in the frame I found that I definately had a problem. Here is what I have come up with so far to try to correct the chain missalignment. This rear mount will move the motor to the left about 5/16ths. That is about all it will go using the stock mounts. I will have to make the front mount with the same offset, then if it's still not enough I might be able to gain some more clearance with an offset sprocket.
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My buds coming over today and we'll be up against the same thing. I'll keep ya posted if we have any blinding flashes of insight/brilliance. Don't hold your breath Ha. One good thing about my friends bike is that the cranks are pretty wide. My schwinn cranks barely clear both sides of the engine. It looks like he has about 3/8 ths on either side. I'll probably make a rubber shim out of an old tire to bump the sprocket outboard. If we can get the tensioner to feed the chain onto the sprocket I guess it would be ok to let it roll off a little sideways. We'll see how it goes. Good luck.
Here's some pics of the torture we had to put his poor bike through to get it to clear the fat 24x3
Here's some pics of the torture we had to put his poor bike through to get it to clear the fat 24x3
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HEy Seca40, did the frame give up any information while you were torturing it? That is a good idea, though. I just stuck an extra nut on each side of the axle. It works but it is a wrestling match every time I put it on! I was lucky too, as my cranks were like your buddy's.
Hi marioaz, the pipe started life as a pocket bike expansion chamber, which I promptly cut into 3 or 4 pieces as soon as I received it from e-bay. I made a new flange for it and welded it to one of the pieces. I need to find some silicon tubing like Ghost0 has on his pipe, to cut down on vibration transfer. The long pipe behind the expansion chamber is 1/2" electrical conduit which I bent so it would clear the peddle crank. Then I brazed the little muffler to the end of the conduit. I have yet to start or run the engine, so I might end up cutting down the length of the conduit. I am not sure how much that length will affect the way the engine will run.
Hi marioaz, the pipe started life as a pocket bike expansion chamber, which I promptly cut into 3 or 4 pieces as soon as I received it from e-bay. I made a new flange for it and welded it to one of the pieces. I need to find some silicon tubing like Ghost0 has on his pipe, to cut down on vibration transfer. The long pipe behind the expansion chamber is 1/2" electrical conduit which I bent so it would clear the peddle crank. Then I brazed the little muffler to the end of the conduit. I have yet to start or run the engine, so I might end up cutting down the length of the conduit. I am not sure how much that length will affect the way the engine will run.
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I got my e-bay gas tank.
I think it will look alright after I paint it. I have to figure out a mounting system for it. I don't think it will hold much more than the stock tank, but I like the way it looks. Also I found an energy drink can I think will make a good muffler. It is made of very heavy aluminum.
I also think the new motor mount has fixed the chain alignment problem. I now need to revise the front mount too.
I think it will look alright after I paint it. I have to figure out a mounting system for it. I don't think it will hold much more than the stock tank, but I like the way it looks. Also I found an energy drink can I think will make a good muffler. It is made of very heavy aluminum. I also think the new motor mount has fixed the chain alignment problem.
I now need to revise the front mount too.Attachments
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Thanks Dan, here are the newest pics. Marvin Martian's Maroon Motorized Madwagon Well, OK, purple.. It is starting to come together, in spite of my slowness. Still need to actually mount the tank. Make front motor mount. Hook up front brake. Hookup electric (including key switch). I won some silicone tubing on ebay to replace the copper fitting in the exhaust.
I am debating on whether or not to put fenders on it. And if I do, should they be high(dirtbike) or low(streetbike) I am sure I will continue to make changes after I get it "done". That is the fun of it.
Well, OK, purple.. It is starting to come together, in spite of my slowness. Still need to actually mount the tank. Make front motor mount. Hook up front brake. Hookup electric (including key switch). I won some silicone tubing on ebay to replace the copper fitting in the exhaust.I am debating on whether or not to put fenders on it. And if I do, should they be high(dirtbike) or low(streetbike) I am sure I will continue to make changes after I get it "done". That is the fun of it.
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Thanks, philymitch. The tank is off of an early (late 70's, I think) JR50 Suzuki. I won it on ebay.
great idea with the tank? do you know how many gallons/litres it is?
the teardrop tank with the kits are SH**HOUSE!!
great build
the teardrop tank with the kits are SH**HOUSE!!
great build
Thanks damonjackson, I don't know the capacity of the tank and it wouldn't suprise me if it is smaller than the stock tank. But it is better looking
The bike looks great, especially the tank. However the pipe needs work for it to work.
The tailpipe is too long and thin.
The header section should be 12" and the stinger even shorter.
The stinger is a "bleed-off" for the chamber and is a critical part in the system
The tailpipe is too long and thin.
The header section should be 12" and the stinger even shorter.
The stinger is a "bleed-off" for the chamber and is a critical part in the system
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IT'S ALIVE. Finally.. I went for my first ride today on the Madwagon. I rode around the neighborhood, then went for a 6 mile ride. Everything went well (I didn't have to walk home) but I need to do some tuning/tweaking on it. I don't think a 49cc motor + a 34 tooth sprocket + a 300lb man add up. The bike never seemed to really come on the pipe, it was sputtering a lot. I guess I need to play with the needle clip for starters. Also, after the ride I went to wallyworld and got a bicycle speedo. I will put it on and ride again before I start tweaking, so I can get a baseline of how my tweaks go. I thought the sputtering could be from the long after pipe as wildemere suggested so I sawed off the pipe about 6 inches back from the chamber and ran it that way. I couldn't tell much of a difference. I will also get a can of carb cleaner so I can check for intake/vacuum leaks...The only down side to this is now that it has gas in it, it's an outside toy!
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