Converting old 1971 Yamaha into moped

Well the subject title pretty much sums it up...Not sure if anyone can help but here goes...For awhile now, I've been thinking about buying an old bike and converting it into a moped. Sounds a little bass-akwards but it's something I really want to do. A couple of years back I was in an accident. Siezures ensued and my license was indefinetley suspended until I'm medically "cleared". I haven't had a seizure in over a year and a half but there is a ton of red tape involved in me getting my license back in the near future. This past summer I bought a scooter (49cc) and it has gotten me around ok. I have a long commute on it back and forth to work everyday and it's just not a practical or comfortable ride. I owned a moped a couple of years back and enjoyed it a lot more. Being that it's a long commute, I want something now that can handle the bumps and has a little "road presence", plus I just feel like working on something different. I bought this old 71' Yamaha DT! 250 the other day. I've stripped it down to frame, handle-bars, seat and wheels. Stripped down, it's not really all that much heavier than a Schwinn Stingray Chopper. I've seen 49cc engine kits on ebay

that come with what looks like everything I would need to to make the conversion.

I've htought about swapping the tires/wheels out for some 26x4 mountain bike tires that would just as easily handle the load and be compatible with the sprocket of the 49cc kit. Any other ideas of potential problems that I would need to overcome.

I know this isn't an actual pre-existing moped like a Trac, but it would technically meet the same description of a moped. Thanks in advance for all responses....

Re: Converting old 1971 Yamaha into moped

wha?

Re: Converting old 1971 Yamaha into moped

Converting old motorcycle (stripped to frame) into a moped (49cc). Going for something in the vein of a Streetmate....Potential problems to overcome. Thanks.

Re: Converting old 1971 Yamaha into moped

Why not just get a moped? If you can scrape up enough money for a new one, you'll have a reliable ride. Of course, if you get an old one and put as much effort into overhauling it as you will surely end up doing by adding a moped engine to an old Yamaha frame, you'll also end up with a reliable machine.

Re: Converting old 1971 Yamaha into moped

I once thought about converting an old tractor into an airplane so I could legally fly it.

Re: Converting old 1971 Yamaha into moped

Good point. It's not that there aren't plenty of mopeds out there that haven't caught my eye. I just want something full-size. Again, the bike is stripped down right now but when I sit on it...It's perfect. Plus it's got these old vintage / retro lines that just appeal to me. Again, not something I HAVE to do and I'm sure it's going to cost, but I've pretty much got my mind made up. I know pictures would probably be beneficial in helping people get the jive of the vision I'm going with here. I'll pull it out into the driveway tomorrow, snap some pics and post them when I get home tomorrow night.

Thanks for the quick response guy.

Re: Converting old 1971 Yamaha into moped

LOL

Re: Converting old 1971 Yamaha into moped

Probably Fred /

I had a DT 125 with a monoshock It was a good bike. The tank was like a magnum I wish I kept it or at least the tank

Re: Converting old 1971 Yamaha into moped

Well if you take a look at the derbi laguna sport, it is built like a motorcycle. You just have to find an engine that will fit correctly in within the space you have.

Re: Converting old 1971 Yamaha into moped

Got plenty of room to work with within the frame. My issue is more with the sprocket and chain feed. The tires on this thing are down right BEASTS and I don't really want to have to swap them out. Thanks again for the responses and again, I'll upload some snaps tomorrow. Good night to all!

Re: Converting old 1971 Yamaha into moped

I have a similar DT125, and I can tell you these would make terrible mopeds. I would at least start with something built for 50cc, like converting an MB5 or something. You're talking about mounting a 2hp motor to running gear designed for 20hp. large tires, heavy frame, etc; a DT250 weighs nearly 300lbs.

Im not saying it can't be done, but for all the time and trouble involved I think you'd end up with a barely-rideable or non-rideable machine instead of a reasonable means of transportation.

Re: Converting old 1971 Yamaha into moped

why not get a swing arm from an FSE1 and put it on another pressed steel frame Yamaha from the the 70's?

Re: Converting old 1971 Yamaha into moped

I don't see the "ped" in this conversion, just a large, heavy motorcycle with a 49cc motor.

Re: Converting old 1971 Yamaha into moped

I'd give my left nut for a FSE1. Fuck, you could have both nuts!

Re: Converting old 1971 Yamaha into moped

If you can come up with $2500 I can get you a really nice one...

Re: Converting old 1971 Yamaha into moped

Line up the chain run with a yardstick and be honest, hoping it will all turn out, has no place here. Weld your motor mount tabs to the frame with some concern given to the beauty of its placement, but the majority given to its function. Use the same rear wheel as the powerplant and you will save yourself several headaches. Everything else is cake.

Re: Converting old 1971 Yamaha into moped

the one in your profile? looks a little worn for 2500.

Re: Converting old 1971 Yamaha into moped

get a streetmate, it's the best of both worlds. some easy mods and you can get well over 30 mph

rides nice and is pretty reliable.

also, parts are easy to find.

hope this helps.

Re: Converting old 1971 Yamaha into moped

what motor are u thinkin of running?

tomos would be the best because it has peadles built in so it could be registered as "moped"

or another option is .....

i have just wat you want ,the work is allready done.

i have a 50cc yamaha motorcycle for sale

1262797529_yamaha_for_sale_001.jpg

Re: Converting old 1971 Yamaha into moped

what Yamaha is that? looks like a little xs400 or 650 but 50cc you say?

Re: Converting old 1971 Yamaha into moped

its a yamaha RX50. theyre pretty uncommon.

Re: Converting old 1971 Yamaha into moped

fallout Survivor /

Why not just start with a bicycle and add the 49 cc engine kit...? The conversion you suggest sounds like more work than it is worth.

Re: Converting old 1971 Yamaha into moped

this is what ya need.

1263010019_vespa_grande_ad_ball_game.jpg

Re: Converting old 1971 Yamaha into moped

rx50 runs the same motor as a ysr 50. they are pretty rare.

On the original topic there is a guy here that mounted a e50 puch motor onto a honda s65 frame. It looked pretty legit for a ratbike.

Re: Converting old 1971 Yamaha into moped

ohh, don't do that to your little DT! You'll kill it's spirit!

Re: Converting old 1971 Yamaha into moped

I suggest fixing the dt, sell it and find one of the 50cc bikes (like the yamaha pic). I've seen some older XR50s out there that I've thought about riding. I think Tomos made a moped dirt bike too. There's lots of options.

I got some questions I'd like to ask too, Is there a law that say's you can't ride the 250? I've heard of people around here who lost there license so they register their dirt bikes with the DNR for off road and ride in the ditch to work.

Are you thinking like a Lifan motor with gears or the 50cc chinese kit with a clutch or a moped engine. I think your best bet is a Lifan (or any brand) 50cc with gears. It would still be slow but the easy to drive. Good luck.

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