Yammy QT50

[Rebel]

I just picked up a 1980 QT50.

Looks a little rough but also looks like it might be fun to play with. There seem to be few performance parts for it but there is a little that can be done to it. I was very surprised to see that it is a shaft drive scooter.

I'll get some photos posted in the next few days.

[jmkjr72]

congrats on the new noped

[Rebel]

Thanks.

This is the absolute first ever 2 stroke for me. The previous owner said that it has a broken reed, claims it is an intake reed that is busted. I'm hoping that does not translate into metal pieces floating in places they do not belong.

If things get too hairy, it may see a transplant. Either another 2 t that has a similar motor mount, Anybody know if the little Honda one is similar? Or I might look into slipping that 150cc GY6 I have into it.

[jmkjr72]

im not sure about swaps even though im working on one right now i didnt realy look at the engine mount
but maybe a tomos swap would work out

as for damage by reed failure i have seen it go good and go bad small chips dont cause issues big chunks can suck big time

you will need to pop the carb off and take the reed block off and post a pic of the damage so i can give you a better idea of what to expect

[Rebel]

OK, sounds like a plan. I've got a pretty busy schedule for the next week or so though.

[Rocketdog]

Shaft drive? I would like to see that. Ahhh I looked it
up for a picture. I remember those.

RD

[Rebel]

The mount looks like a GY6 one, so, I'm thinking, do what I have to to get it registered and then look at putting the 150 in it.

[90GTVert]

www.jacksscootershop.com/images/Yamaha_50/78_QT-50_red.jpg

I don't know anything about those in particular. If getting the performance you want is going to be difficult, you could swap in the Honda/Pitbike/Midbike/Trail Bike style engines. You'd need to convert to chain drive, which shouldn't be a big issue for that. I've fit those engines onto go karts and even stuffed one into a really tiny little bike, so this should be cake. A 125cc with the 4 speed transmission should keep up with a GY6 150 pretty well with the right sprockets. With some of the big bore and stroker stuff out there, you could easily surpass the GY6s. I like CVTs, but a standard transmission puts power down nice and swapping front or rear sprockets is easier than doing final drive gear swaps.

[Rebel]

Here are a few pics of the little noped. The throttle cable is broken, but the choke seems to work and that is the one that is not available.



A singe spring and shaft drive



Ya, the seat is trashed

Attachments:

[Rebel]

mounted to the frame with a single bolt

[90GTVert]

Nice project. It's a little rough around the edges, but that makes it cooler to show off the difference when it's all done. ;D

Checked the motor out yet?

[Rebel]

I've just turned the crank, it seems to have decent compression.

[wortleees]

Nice ride. Moved to MI tobe with my sweetie, maybe I'll find something this winter. Left my 2 150s
in TX with my kids. Miss them nice areas up here to ride.

[Rebel]

I've been looking around for parts for this little guy. I found this place called peeweecycle and it has the parts.
peeweecycle.com/miniracer-pw50engine.html

moped army has some suggestions for pumping it up.
www.mopedarmy.com/forums/discuss/7/104409/104233/

moped riders association has the actual Yamaha shop, owners manual and wiring diagram to download, very helpful.

[90GTVert]

I hope that's one bad mutha with the price of those BBKs. The bored over ones aren't bad prices.

From moped army...

"50mph is a lot of fun, but think about your brakes, and how tiny the QT is."

That's intelligent thinking, but it will hold you back. When I first got my 20MPH cateye midbike I thought getting it up to 50MPH would be cool but I was worrying about the brakes and 6" wheels at those speeds. I eventualyl quit worrying about that stuff. Now it wheelies every gear and does better than 50. Yeah, the brakes are shotty at best. At one point it had no brakes and you had to put your feet down to stop lol. In all honesty it's one of the most fun things I've ever driven. It scares everyone that's ever got on it, and that's why it's so fun. Of course there are limits, but you'll find 'em after it's built. You can always open the throttle less.