$100 Well Spent: Yamaha U5E

[Charlie78]

Found this scooter in an auction at a local trade school. The listing had 2 blurry pictures and offered no information, other than saying “parts were taken off but included in a box”. I bid on a few things. Won them all. $12 for 2 commercial stand mixers, amazing in its on rite. And $100 for this 1966 Yamaha U5E with 702 original miles. It even came with the original owners manual and shop manual.
It’s in pretty good shape, the only parts actually missing are a mirror and the oil cap. Otherwise anything missing in the pics is there.
I am totally blown away with what I ended up with here. I figure I’ll port the engine, get it a proper pipe, kinda do a light restoration everywhere else, but keep the original paint as much as possible. Its powered by an electric start, 50cc, disk-valve, engine with a 3sp semi-auto gearbox. Should be fun. So, what do you think? Do you dig vintage scooters?

 

[Chainlube]

Nice find, it's been inside it's whole life. Can you say jog pipe?

 

[Karl Snarl]

Found this scooter in an auction at a local trade school. The listing had 2 blurry pictures and offered no information, other than saying “parts were taken off but included in a box”. I bid on a few things. Won them all. $12 for 2 commercial stand mixers, amazing in its on rite. And $100 for this 1966 Yamaha U5E with 702 original miles. It even came with the original owners manual and shop manual.
It’s in pretty good shape, the only parts actually missing are a mirror and the oil cap. Otherwise anything missing in the pics is there.
I am totally blown away with what I ended up with here. I figure I’ll port the engine, get it a proper pipe, kinda do a light restoration everywhere else, but keep the original paint as much as possible. Its powered by an electric start, 50cc, disk-valve, engine with a 3sp semi-auto gearbox. Should be fun. So, what do you think? Do you dig vintage scooters?

BONER!!!!! YOU F'N SCORED BIG!!!! OMG!!! I'M JEALOUS!!!! LUCKY F'N YOU!!! YOU BASTARD, YOU GOT ONE HELL OF A DEAL!!!! I'VE BEEN LOOKING FOR STUFF LIKE THAT FOREVER!!!!!

 

[Cisco]

YOU F'N SCORED BIG!!!!

I'll say! Is this the 12v with electric start? The 'U-5 (e)' on the manual indicates it is. Auto Lube, no fuel mixing (nice). Disk valve instead of reed, another plus.

I figure I’ll port the engine

Why do anything to the engine? Japanese engineering, why mess with it?

Can you say jog pipe?

You mean something like this?

Motorcycle Exhaust System Muffler Pipe for Breeze Jog models 50CC

 

[Karl Snarl]

I'll say! Is this the 12v with electric start? The 'U-5 (e)' on the manual indicates it is. Auto Lube, no fuel mixing (nice). Disk valve instead of reed, another plus.

Why do anything to the engine? Japanese engineering, why mess with it?

You mean something like this?
View attachment 168155
Motorcycle Exhaust System Muffler Pipe for Breeze Jog models 50CC

I can't wait to see what you get it doing!!! i'm excited to see the next thread on this ride!!!!

 

[Mossy]

I'll say! Is this the 12v with electric start? The 'U-5 (e)' on the manual indicates it is. Auto Lube, no fuel mixing (nice). Disk valve instead of reed, another plus.

Why do anything to the engine? Japanese engineering, why mess with it?

You mean something like this?
View attachment 168155
Motorcycle Exhaust System Muffler Pipe for Breeze Jog models 50CC

Those 'auto mix' can and usually plug up and the mechanism can fail with out you noticing it... So pay special attention to that... My 72 Kawasaki got premix because it had that happen and I got tired of cleaning and rebuilding the acient auto mix setup

 

[Cisco]

I got tired of cleaning and rebuilding the acient auto mix setup

Yes, convenient, but just one more thing that can go wrong. I had a Kawi 90 with a Super Lube. It never had problems. Just lucky, I guess.

 

[Mossy]

Yes, convenient, but just one more thing that can go wrong. I had a Kawi 90 with a Super Lube. It never had problems. Just lucky, I guess.

The 60s and 70's were just coming up with it... By 80's and 90's the game changed on everything.... You either took very good care of it or got lucky... I would flush it out and any dirt or moisture would cause it to act up on my G4 100... I had to use a special oil viscosity... So it got pre mix LOL

 

[Charlie78]

I'll say! Is this the 12v with electric start? The 'U-5 (e)' on the manual indicates it is. Auto Lube, no fuel mixing (nice). Disk valve instead of reed, another plus.

Why do anything to the engine? Japanese engineering, why mess with it?
>>>

Re: Porting, (e), jog
It’s been recommended to me to go thru the engine, to check the bearings and seals. These may need to be replaced due to sitting for quite possibly 5 decades or so. According to some guys that have had these engines apart, smoothing out the transfers and matching the cylinder to the crank case is worth doing since I’ll have it apart anyways. Nothing radical, just smoothing out the casting.
Yes, it is the electric start model
The Jog pipe is someone’s recommendation. I don’t know a ton about them. However, I do hear you can see some bottom end gains from having a proper expansion chamber using the original header length. Doesn’t seem like a terrible idea. I could make a new header so I don’t need to chop up any original parts and use the expansion chamber from the jog perhaps

 

[DieselTech]

Re: Porting, (e), jog
It’s been recommended to me to go thru the engine, to check the bearings and seals. These may need to be replaced due to sitting for quite possibly 5 decades or so. According to some guys that have had these engines apart, smoothing out the transfers and matching the cylinder to the crank case is worth doing since I’ll have it apart anyways. Nothing radical, just smoothing out the casting.
Yes, it is the electric start model
The Jog pipe is someone’s recommendation. I don’t know a ton about them. However, I do hear you can see some bottom end gains from having a proper expansion chamber using the original header length. Doesn’t seem like a terrible idea. I could make a new header so I don’t need to chop up any original parts and use the expansion chamber from the jog perhaps

I wouldn't tear the engine down, I'd get it running & ride it a bit b4 you make that big of commitment to the scooter. As for the auto mix I would not trust it after sitting, i would use premixed fuel. I picked up a 68 Suzuki moped for my cousin & it had 312 miles on it, I rebuilt carb, flushed tank & replaced tires & brake shoes & it's still running to date & it Sat for like 18years.