Really appreciate this video man! Its been 20 years since i had my z50 working. It's a 79 and i had no idea about the different rod lengths. Paid 2 different people to get this thing back on the road, one kept it for 3 years and did ABSOLUTELY NOTHING! Took it to a guy that lives down the street. He was working on another one when i dropped it off. The asshole needed a carb for the other one and ended up buying a cheap POS off amazon that woukdnt work on the other one, so he threw MINE ON IT and gave it to the people as "REPAIRED" and stuck the new piece of shit on mine, which it still didnt fit, so he took the damn upper engine mounting bolt out to tip the engine down a little so it'd fit. I took it back immediately. I had given him a brand new enerpac hydraulic pump($600 dollar value). He said he put a new jug and piston kit in it, but couldn't get it running. I tore into it myself finally, found that not only was there no new jug or piston but that he'd also stuck the thing back together 180° off on the timing! Im getting older and have a disease thats measing up my spine and id REALLY like to ride this thing again before i cant anymore. This thing used to ride in the back of my cj5 because i had a broken gas guage and ADHD which is a TERRIBLE combination! It saved my bacon so many times and because i always had it with me, i used it so much more because i had it when the mood took me. If i cant get this thing running soon, im going to sell it and buy a cheap chinese copy. I know how disgusting that sounds. I woukd have beat my ass for saying that 20... shit, even 10 years ago, but that was a ton of health and a long time ago. I dont have the income anymore to afford a real one, so if i cant fix the one i have... 🤷 Sorry for the huge comment! Wasnt my intention. Its an old video and apparently i needed to vent a bit. I dont know if youre still doing this 3 years later or not, but if you are, i may indeed need some help with this. I dont have a ton of money, but i have a parts bike and a bunch of other misc. parts if i needed to bother you for help. Ive tried the "someone local" thing and t no avail! Kinda running out of time and options.
I'm glad I watched this video. I just got a 74 XL70, and will be attempting to get it running in the next month or so. I have never worked on these little engines, but I'm learning tons on RUclips. I had no idea about the long and short connecting rods based on the year. I don't know that I'll be needing to tear into the engine, but the more you know, the less you screw up. Thanks for the education, and the links to reputable parts places.
Great video I wish there were more honesty guys like you doing this vintage atc and mini bike restorations you doing a great job keep up the good work👍👍👍
man Im glad I bought a shed full of parts for these bikes years back, never thought parts would get this scarce. used to buy heads for 10.00 , complete engines for 125.00 frames for 50.00.
Another really informative video Josh. I have a 1970 CT70 with a 140cc motor. Now I am doing a 1972 CT70 and I would like to keep it stock. Currently the motor is locked up. I will take it apart tomorrow and assess it.
The top end kit works for all 70cc they are made for short rod engines like this the Honda 90cc big bore kit also works because the stroke is the same just the bore.
I just ran across this video and I rebuilt my 1971 with one of these cheap amazon kits last week. Now I am really confused because mine is running really good....
thanks for putting these honda vid out there you are the man when it comes to these lil bikes i have watched alot so far i have a 1969 z50 and 2 1971z50 also a1977 z50 i am working on the red 71 now so ill be watching thanks alot honda man......
Thanks for the great information. I have a 1970 ct70 motor on my Z50. Would you know if I can just change the cylinder head and piston to the 50cc size.
Yes you can, it is a bolt on procedure.Youll need a 39mm jug/cylinder too for the 49cc setup. Just follow the tips in the video and buy your parts from the vendors I show based on year of engine.
Good video, I have one of those kits, do you think I can use the parts from the kit except for the piston and buy a correct piston from a different manufacturer ?
The jug could be used (But double check that it is true/flat on machined gasket surface etc). I do not know of a piston that is out there that is a swap in to work with the short rod and CRF70/XR70 style aftermarket heads in those kits
No, 1982+ used a flat piston, longer Conrod and the small combustion chamber you find on the aftermarket top end kits. The domed piston on a 73 will not play well in a kit head
Really appreciate this video man! Its been 20 years since i had my z50 working. It's a 79 and i had no idea about the different rod lengths. Paid 2 different people to get this thing back on the road, one kept it for 3 years and did ABSOLUTELY NOTHING! Took it to a guy that lives down the street. He was working on another one when i dropped it off. The asshole needed a carb for the other one and ended up buying a cheap POS off amazon that woukdnt work on the other one, so he threw MINE ON IT and gave it to the people as "REPAIRED" and stuck the new piece of shit on mine, which it still didnt fit, so he took the damn upper engine mounting bolt out to tip the engine down a little so it'd fit. I took it back immediately. I had given him a brand new enerpac hydraulic pump($600 dollar value). He said he put a new jug and piston kit in it, but couldn't get it running. I tore into it myself finally, found that not only was there no new jug or piston but that he'd also stuck the thing back together 180° off on the timing! Im getting older and have a disease thats measing up my spine and id REALLY like to ride this thing again before i cant anymore. This thing used to ride in the back of my cj5 because i had a broken gas guage and ADHD which is a TERRIBLE combination! It saved my bacon so many times and because i always had it with me, i used it so much more because i had it when the mood took me. If i cant get this thing running soon, im going to sell it and buy a cheap chinese copy. I know how disgusting that sounds. I woukd have beat my ass for saying that 20... shit, even 10 years ago, but that was a ton of health and a long time ago. I dont have the income anymore to afford a real one, so if i cant fix the one i have... 🤷
Sorry for the huge comment! Wasnt my intention. Its an old video and apparently i needed to vent a bit. I dont know if youre still doing this 3 years later or not, but if you are, i may indeed need some help with this. I dont have a ton of money, but i have a parts bike and a bunch of other misc. parts if i needed to bother you for help. Ive tried the "someone local" thing and t no avail! Kinda running out of time and options.
I'm glad I watched this video. I just got a 74 XL70, and will be attempting to get it running in the next month or so. I have never worked on these little engines, but I'm learning tons on RUclips. I had no idea about the long and short connecting rods based on the year. I don't know that I'll be needing to tear into the engine, but the more you know, the less you screw up. Thanks for the education, and the links to reputable parts places.
Great video I wish there were more honesty guys like you doing this vintage atc and mini bike restorations you doing a great job keep up the good work👍👍👍
man Im glad I bought a shed full of parts for these bikes years back, never thought parts would get this scarce. used to buy heads for 10.00 , complete engines for 125.00 frames for 50.00.
Another really informative video Josh. I have a 1970 CT70 with a 140cc motor. Now I am doing a 1972 CT70 and I would like to keep it stock. Currently the motor is locked up. I will take it apart tomorrow and assess it.
This was really helpful! Thank you for taking the time to put this video together.
i bought a 1970 ct70 w/ the china top end…. ran terrible noisy tryin to bring to back to original great info im sure it will help
The top end kit works for all 70cc they are made for short rod engines like this the Honda 90cc big bore kit also works because the stroke is the same just the bore.
Thanks Josh , i was looking hard at these , thank God i did not pull the trigger . Great video !
I started doing big bore builds over 10 years ago, sir ... I sure have a lot of extra parts
I just ran across this video and I rebuilt my 1971 with one of these cheap amazon kits last week. Now I am really confused because mine is running really good....
Very good video, folks need to know this, I have learned through experience
thanks for putting these honda vid out there you are the man when it comes to these lil bikes i have watched alot so far i have a 1969 z50 and 2 1971z50 also a1977 z50 i am working on the red 71 now so ill be watching thanks alot honda man......
I have vintage bikes so I did the cylinder head myself and bought a NOS Honda old dome piston.
That was the right choice - LOL
Thank you for the information Very informative
Great information Josh!
Great info thank you!
Thanks for the great information. I have a 1970 ct70 motor on my Z50. Would you know if I can just change the cylinder head and piston to the 50cc size.
Yes you can, it is a bolt on procedure.Youll need a 39mm jug/cylinder too for the 49cc setup. Just follow the tips in the video and buy your parts from the vendors I show based on year of engine.
Good video, I have one of those kits, do you think I can use the parts from the kit except for the piston and buy a correct piston from a different manufacturer ?
The jug could be used (But double check that it is true/flat on machined gasket surface etc). I do not know of a piston that is out there that is a swap in to work with the short rod and CRF70/XR70 style aftermarket heads in those kits
Thanx Alot . .
Is 2fastmoto a reputable kit just popped up in my search they specifically point of that it is for my short rod motor. Thanks in advance
Pretty sure they are out of stock once you put it into the cart. They migrated to another website too
Woll a Chinese head fit a 73 Z50? Or can the cam journals be repaired? I'm having trouble finding a new head. Thanks
No, 1982+ used a flat piston, longer Conrod and the small combustion chamber you find on the aftermarket top end kits. The domed piston on a 73 will not play well in a kit head
@@VintageHondaMinis thanks. Is there a way to identify the proper head? I see some used ones on ebay but they all say z50. No year😆
Does the Honda z50ak2 take a battery? Thanks
No - The k1 does though.
I'm going to link your vid in my video's description if you don't mind so people know not to install these Chinese kits.
Go ahead - No problem
✌️🥸 💯