Dongfang SST DF50 scrambler
 

So a few weeks ago I did a trade for a 49cc scooter I’ve wanted to mess with since I first saw one. The so called “baby Ninja’s” and was able to get a non running Dongfang SST cheap. Actually the only one I’ve seen first hand here in Maine.
Attachment 1121

It wasn’t running for several reasons, but primarily because the intake manifold was full of cracks and the carb literally had dirt in it.

This scoot is still a work in progress and I’m hoping that folks on this forum can give me some guidance. I’ve ridden motorcycles since I was a kid, but have gotten more interested in scooters in recent years.

I love the bones of these baby ninjas perfect for an urban scrambler/ADV build, so... I ripped off all the cheap brittle plastic fairing, pulled all the “anti pollution” stuff and cut and welded the PAIR closed. I added a big bore kit, and 22mm carb, and have also just replaced the very warn/flat roller weights in the variator going from 4g to 6.5g. I also added some inexpensive fat bars (I could not handle being hunched over) and the headlight was already toast so have been fabricating a bracket for a 9” LED bar that’s 1400 lumens. The scooter is great and I am going to keep going on it as a scrambler, I weigh 185lbs and it goes 45mph on flats and just under 30 up a steep hill. So I strapped on my tank bag and tail bake with tools and parts and put it though the paces, and I like it.
Attachment 1120

Now I’m looking at what tires to run on it so I can do some light trails. I also am thinking about painting the frame Husqvarna orange and the rest black. So at this point I am starting to grasp at air in how to proceed and am looking for any input, ideas, concerns, etc. The fact that I barely have $200 into it is mind blowing to me, and waaaay better than going to the movies 8 times!

So please give me some suggestions.

I’ve been tuning the scoot using an adjustable CDI, and think I’m getting it dialed in but I’m not finding much yet online on just where I need the curve. Any suggestions? There are probably lots of folks who have this down, I’m looking for your pointers.
https://youtu.be/REP6smLVpUs


Not sure if you can see clearly but this is where I’ve set the advance it’s about centered on the middle between idle and full rpm, is there a way I can mark on the wheel the degrees of advance & retard so I can do this better?
https://youtu.be/QOaHCEiXSJc

It's been awhile since I've worked on a 4 stroke, so my knowledge is very limited.I did a bbk on a Zuma 125 awhile back and we used a degree wheel bolted in place of the cooling fan. We experimented with different ignition curves with an adjustable CDI. YouTube had a great how to but I cannot recall the links name. Also, Scrappy Dog.com had a how to listed at one time for 4 stroke GY6 tuning. Finally Moped Army has a super detailed how-to section but I'm not sure how "4-stroke" they go since they cater to old school mopeds. And yes, a GY6 motor can be very reliable, just the wiring can be sloppy sometimes causing other issues. I hate making custom wire looms but I've done my fair share. I actually had a Yamaha Zuma with a factory wiring problem in the loom from sloppiness!