Just what is a "Chonda XR107"???
It is a Honda XR70 with a Chinese Lifan 107cc motor bolted on (thus, Chinese Honda).
This baby is now one rockin' bike, with lots of torque, and a clutch and four speed gearbox. Just crack the throttle and the front end lifts up!!
The complete motor was about $400 from "motortoysdirect.com", plus a few bucks for the clutch lever and cable.
After the original 70cc Honda motor was wasted by a rock through the crankcase, we decided to do this rather than sell it for scrap. After some internet research, we went with this setup. But there were problems….
The first problem was NO WIRING DIAGRAM was provided. Motortoysdirect was NO HELP AT ALL!!!! We called, begged, etc. but they couldn't or wouldn't help us. Eventually, Uncle Steve and Dad took the magneto apart to figure it out. That, along with some CDI wiring diagrams found on other Lifan-related Web sites, gave enough clues to get it running.
The next problem was the new carb didn't fit the old intake manifold. Uncle Steve "elongated" the holes in the carb so it would bolt up to the original intake (we wanted to do this so that the original air box and air cleaner could be used).
Next, the new BBR skid plate wouldn't fit with the electric starter motor in the way. Since the Chonda doesn't have a battery, we didn't care about the starter. So, off it came, and a steel plate was fabricated to cover the old location. A little trimming of the skid plate brackets with the cutoff saw and everything fits; no more damaged motors due to hitting rocks!!
Everything seemed OK until we put it all together...it just had no "balls". While playing with the carb adjustments, it ran great. With the air cleaner on, not great….so TRIM THE AIR CLEANER COVER!!! We hacked away lots of the cover, pulled out a screen, and really opened her up (all the foam is still there). With a little more air coming in, it ROCKS!!!
All was well for a couple of weeks until…...SPOKES ARE BREAKING!!!! We don't know if it is the age of the bike (2001), the additional power, or if the spokes were already a little loose, or a combination of all the above, but 16 of 36 spokes were busted. A trip to the Honda dealer to buy replacements and then the next test of our resolve begins--truing the wheel…
Again, the internet came to the rescue: http://www.off-road.com/dirtbike/
This site has a great column (Nov. 2000) on truing wheels that saved our bacon. Following the instructions (and building a wood cradle to spin the wheel in) enabled us to true the wheel in about an hour, and the spokes ring like guitar strings!!!
All that's left is to see what happens/breaks next, with some field trials later this summer!!!