My latest project: '76 Honda Z50 w/ 125 lifan, Lots of Pics!!!

[81Rmachine]

I just picked up this '76 a few weeks ago for $300 in non running condition and pretty beat up. I was told it didnt run and needed a top end. I drug it home and found out it was ill-maintained and the timing chain was loose enough to slip a tooth. It had no compression so first thing i usually check is valve lash and timing and sure enough it was a full tooth retarded. I reset the timing tightened the chain and got it running although it wasn't the strongest running it didn't burn oil and ran pretty smooth, but I already had a lifan coming in the mail. The motor isnt going to collect dust its going to my brothers '77 Z50 resto. Im normally not one to part something out but this bike is a '76 a pretty common year, not that rare, and beat up so far from a collector and besides I was gonna build something to actually ride.

Now, the build, It actually looks pretty good from a distance, but up close everything was kinda thrown together, nothing was bolted together right, the tank was pretty dented although surprising clean inside. I wasnt planning on a complete resto-mod at the moment, just to get it mechanically sound and looking complete, but i wanted to start with a good base so I took it down to the frame, blasted, painted, and did some machining for the swingarm. It was pretty sloppy so I turned some bronze bushings on the lathe and pressed them in. You can see in the pic how oblonged the hole was on the drive side and ideally you would bore the hole bigger but I didnt have a good way of doing that, I could have mounted it on the mill somehow, but didn't think it was worth the headache and i sure as hell wasnt going to use a drill bit cause then both side are out of alignment, but the bronze worked out very well, no more play.

The factory suspension is pretty soft and Im about 195 so I turned some spacers on the lathe and slotted them on the mill to fit under the springs. I was very satisfied with how the suspension upgrade helped it doesnt bottom out near as easily and its actually stiff enough i can carry a decent wheelie, otherwise it was too soft and all over the place and theres still plenty of room before coil bind. Heres the spacers, More pics!

The front forks weren't the typical blown out wore through the chrome forks you find on a Z50 but they werent perfect so i rebuilt em. I got the fork parts from Dr. ATV including plastic sliders, seals, and the upper sliders located at the pin which were only put in ct70s. I tumbled all the parts to get all the nasty old grease off of them. The factory hole between the fork tube and spring seat were no where near aligned with the new bushing and i needed a longer pin to hold the new bushing in place so I used an oversize drill and went through them all and turned my own solid steel pin with a bit of press fit. If you rebuild any Z50 forks, I would highly recommend to put the ct70 sliders in! the factory plastic lowers just aren't enough. The end result was some very smooth working forks, and the nicest riding z50 I've been on.

The bearings were in good shape so i left them, the front brake had been disconnected so the drum was rusty so I chucked it in the lathe and cleaned it up, I washed up the brake drums and reassembled with fresh grease in the cams and pins. It finally felt like a good solid roller.

I dont want to make this first post too long cause i want to keep everyones interest of course pictures help, but i do have the machine in riding condition as of now and absolutely love it. I've made pretty good progress considering its been a month since I got it. I thought I'd see what you guys thought first and then ill post up the whole engine installation next along with any machining and modifying it took to make it all happen, I appreciate any input and let me know if you have questions, Im hopin to find atleast some Z50 gurus on this site!

[atc350xer]

Really nice work... these minis are fun as hell, right?

[81Rmachine]

Really nice work... these minis are fun as hell, right?

They are so darn fun to ride especially with an engine that can actually produce more than 3hp!!! Ill go ahead and post some pics of the engine. The only mod the engine took was grinding down a left side case bolt by the rear sprocket so the engine could slide in the frame otherwise it bolted right in. The intake and carb were a different story and required quite a bit of modifying to work. The carb sat too high and hit the tank so I angle milled the base of the intake 3 degrees and the carb flange back up 1 degree to level the carb out some and this gave me a bunch more room.

I ordered up the angled petcock from T-bolt and looped the fuel line around the carb, I also had to tweak the petcock flange back and out some to clear the carb and it barely fits but here it is with the engine installed and all hooked up.

The exhaust is an el-cheapo $50 ebay special intended for a CRF 50 that I shortened and tweaked to fit. It sounds more like a 450 than a 125 now! The wiring was kind of a nightmare at first, but i got it worked out. Someone had previously butchered it and drilled a hole in the headlight bucket for their own toggle switch so to make use of this ugly hole I found a 12v green led at the parts store and utilized the neutral wire from the lifan and its kinda nice havin a neutral light. I replaced the factory on/off switch with a 78 style hi/lo beam and a dual filament 35w 12v halogen bulb which i am very impressed with, its about twice as bright as the 6v factory sad excuse for a headlight on my 81 XL500s which was actually built for half street use. The lifan is an unregulated 12v system so i used dr. atvs voltage regulator and for anyone using lights with a lifan MAKE SURE TO USE THE WHITE WIRE!!! The white wire must be connected to the lower left terminal on the reg in addition to dr. atv's instructions or you WILL NOT have regulated voltage. The rear taillight is also from dr. atv and my only complaint was the ground wire was simply wrapped around the spring behind the bulb so i soldered it on. Since I went to a hi/lo beam switch i still wanted to be able to switch off my lights so i rigged up a hidden toggle switch under the tank.

The kickstand I got was also from dr. atv and was anything but a simple bolt on. I had to mill about 100 thousandths off each side of the clevis and the shoulder bolt intended for it was too big to even drill the mount to fit. I drilled the hole in the footpeg mount as big as i felt safe (about .425) and i turned a stepped bronze bushing to put on a regular metric bolt to keep it from riding on the threads and along with a bunch of grinding to fit against the footpegs it worked.

IDK if anyone else using lifans has noticed lower gearing but the factory 50 was geared 12-37, the lifan came with a 14 so i tried it and it was horribly low. I bought a 29t rear which helped immensely and went to a 16 front and it will now do about 50 and the engine actually feels stronger with some taller gears, it actually has something to work for haha. I simply have some jetting to do yet since with the K&N air cleaner and the big bore pipe, it breathes much better now so im tweaking the carb but otherwise its a great running engine and im very impressed with its power and reliability. Ive had plenty of engines apart from most major brands and i sure wouldnt go as far to say its the same quality but its pretty damn good for the money and im pleased with it. Heres a few more pics of it now, let me know if you have any questions! Comments welcome as well.

[G-Ram]

that thing is saweeeeet! growing up, my best friend had a z50, and man I was jealous of him.. Well, now I'm gonna have to go buy one haha