Not sure if this can classify as Mini bike, so posted this here to potentially maybe keep out of trouble. ''LOL''

I74

Active Member
#1
I Had a guy get in contact with me awhile back on restoring a 1979 QT 50 Yamaha Moped.
It had been sitting since 1983, & I did ''a- lot'' of work on it getting it up to par.
Runs really good now, & he cruises with me, on one of my Minis from time to time , on our finished Subdivision streets.
We modded a few things on it so far, including a performance exhaust, & K&N type filter & my own Hi flow induction for it.
Runs around 30+ so far, & he ordered a 70cc kit for it, plus a high flow intake,, & up graded Chikuni carb.
With the 70cc mods ect., they supposedly run around 50 mph.
That would definitely be something to see !!
I did replace the tires already with quality hi speed ones ,that are supposed to hang @ that speed.

Am supposed to have the top end kit here Mon.
Will keep you posted. ;)

I
 
#3
The Yamahopper! Had one back when and used it as a pit bike. 50 MPH? Don't think you can get to go that fast, they are geared pretty "low" for a top speed of just under 30. At 50 that engine would be wailin'. Have fun. It's pretty good for what it is. Lately I have been using that Azusa Engineering minibike I built a few years back, works good and everyone who sees it's "highland green" color wants one. You can still buy all the parts new to build one, even a kit with all the bits you need. The photo below shows it with a Titan Engine from Harbor Freight, but now I replaced that with a "good 'ol USA" vintage Briggs and Stratton 5 HP flat-head powers it. It just looks more richeious and I removed the behind the seat mounted fuel tank. Everryone smiles when they see it. Brings back a lot of fond memories.

P1011411_result.JPG
 
#4
Trying to relive my glory days but but better. Here is a list of the parts I have so far. Malossi 70cc top end,Malossi high compression custom squish oring head,mlm intake and vm18 carb, pw50 gears, stiffer clutch springs. Ordered a hand made Jemco exhaust will be here in a month. It’s an addictive little machine
 

I74

Active Member
#5
Yea ,, I was wondering that myself with the gearing ect...
I did take the diff. apart & grease it. ''Pretty much checks out like new''.
The guy that owns it, will be signing up & jumping on here,, with more specifics/research of up grades that he has ordered, / will order for it.

P/S,,
That Azusa is sweet.
Would love to see a new pic with the 5hp Briggs !
 

I74

Active Member
#6
Trying to relive my glory days but but better. Here is a list of the parts I have so far. Malossi 70cc top end,Malossi high compression custom squish oring head,mlm intake and vm18 carb, pw50 gears, stiffer clutch springs. Ordered a hand made Jemco exhaust will be here in a month. It’s an addictive little machine
Hi Fred,, ''Welcome to the party''!! :)
I
 

jeep2003

Well-Known Member
#7
Nice bike we had one put like 3k miles on it in 2 years between me and my brother It was stock except i put a tecumseh carb on it. It was a good bike the 2 speed was cool
 

Attachments

#8
My dad has one sitting in his garage, not that nice though. He bought it at a garage sale about 20 years ago for 50 bucks I think. The guy said it needed a CDI and some re-wiring. Well, my dad bought a new CDI for it, bundled the wiring back up, cleaned out the carb, got it to pop a few times and there it sits. I heard there's something about the gears that a class of racers like, I think there's a gear that is interchangeable with maybe a PW50 or something that gives it a little more top end?. A lot of us mini bike folks have or have had mopeds and scooters too so I don't think you'll get too much flack for posting here, have fun!.
 
#11
I Had a guy get in contact with me awhile back on restoring a 1979 QT 50 Yamaha Moped...
Nice bike with thoughtful mods. I have the Honda version of this bike, an NC50 Express. I've always thought of this type of bike as a scooter rather than a moped, because thy cannot be pedaled, but I'm not sure that scooter is the best description either. Maybe that's what makes them special. They don't fit into any of the normal categories. :D
 
#12
Back in the day when I was still in high school and I was working at a dealership, we called the Express a "Noped" rather than Moped. Our customers couldn't seem to get it through their head it didn't have any petals, therefore California law considered it to be a "motor-driven cycle" requreing a class 4 (now class M) drivers license to operate. We'd roll them out the door and a frantic pace (very popular) and a few of our customers came back with tickets from the local police department for operating a "motorcycle without a license". We would try to explain that the rider needed to get a motorcycle license to ride it when they bought it but that usually went in one ear and out the other. We finally produced a form that said something like "You must have a class 4 (now class M) endorsement to ride it to sign when they bought it. When they came back all PO'd about this we would show them the signed form to we we would respond (nicely) we told you so! Usually went over like a lead balloon. They couldn't understand and that Mo-PED meant motor + petals and the moped could be propelled forwards with only human power. Not so with the NC-50 or Yamahopper. Motor driven only. At the same time we also sold the "Hobbit" a real moped, I'd bring them over to it and show them the difference. They would argue and I'd say here, roll it outside jump on it with no key and petal it around the parking lot and say "Try THAT with an NC-50" - see the NC-50 is a NoPed, many of the still couldn't comprehend the idea.
 

I74

Active Member
#14
Back in the day when I was still in high school and I was working at a dealership, we called the Express a "Noped" rather than Moped. Our customers couldn't seem to get it through their head it didn't have any petals, therefore California law considered it to be a "motor-driven cycle" requreing a class 4 (now class M) drivers license to operate. We'd roll them out the door and a frantic pace (very popular) and a few of our customers came back with tickets from the local police department for operating a "motorcycle without a license". We would try to explain that the rider needed to get a motorcycle license to ride it when they bought it but that usually went in one ear and out the other. We finally produced a form that said something like "You must have a class 4 (now class M) endorsement to ride it to sign when they bought it. When they came back all PO'd about this we would show them the signed form to we we would respond (nicely) we told you so! Usually went over like a lead balloon. They couldn't understand and that Mo-PED meant motor + petals and the moped could be propelled forwards with only human power. Not so with the NC-50 or Yamahopper. Motor driven only. At the same time we also sold the "Hobbit" a real moped, I'd bring them over to it and show them the difference. They would argue and I'd say here, roll it outside jump on it with no key and petal it around the parking lot and say "Try THAT with an NC-50" - see the NC-50 is a NoPed, many of the still couldn't comprehend the idea.
Back in the 70's here in Iowa,, min. age for riding an Express ect. , was 14,, & I believe all you needed was a learners permit.
 
#15
what wheels are those on the green Azusa bike?
https://azusaeng.com/product/azusas-ten-incher-steel-wheel/

Azusa's 10" steel wheel. The link to take you there is above. Available in chrome or black, so far no complaints. Just be careful when mounting the sprocket it's true with no runout. When I first built this bike I didn't check that and had a badly stretched chain in the first ride. Now that I got
that ironed out the minibike is great. Everyone who sees it wants one, I tell them where to get the kit. I believe our host of the board (this website) can get a kit for you. You will need to paint the frame, Highland Green is a Ford color, the Mustang in the Movie "Bullet" is Highland green. At least that's what I used. The Briggs & Stratton 5 HP engine isn't as "punchy" as the Harbor Freight Titan, but it looks the part.

Here's what I am talking about regarding runout:


Bumblebee2
 
#17
Got the gears pressed & swapped today, & have the PW 50 gears set & ready to go on my buddies QT- 50
Definitely have to be very precise & easy with pressing the ring gears off & on the shafts, with using constant propane torch heat on the ring gears.

They didn't send a new wristpin / rod - cage bearing yet though, so we have to wait a bit before we can put the Malossi 70cc ''Hi comp'' top end on it.
Piston to head clearance is definitely going to be a ''must check'' also,, with this ''hi comp''/ shaved head set up.
 

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