Possible replacement CDI for Sierra?!

[obso]

Originally Posted by azriel

I suspect that the impulse from cdi to coil is too weak , or that i need a stronger coil? Ill try to measure the impulse voltage from the zongs cdi and the lifans cdi and compare them.

Maybe a stronger coil would do the trick?

A better sparkplug?

Any opinions/sugestions are welcome!

P.S. will upload wiring diagram,didnt make any yet.

There's a couple things it might be. The first thing I would look at would be the coil. You need to make sure the impedance(ohms) of the primary windings on both coils are close to the same. It might be easiest just to swap your coil to the lifan unit and try it if you have access to one.

Could also be that the pickup coil voltage on the two bikes is too different. Hard to know without measuring it on both bikes or somehow finding specs.


Are you sure your zong cdi was bad? I had a problem on my sierra where I had weak spark but not enough to run the engine. I assumed it was the cdi at first but when a new one had the same weak spark I changed the pickup coil and it fired right up.


Edit: And don't overlook the obvious too. If your bike has been setting there not running for over a year its very possible something gunked up in your carb and is causing issues. can't hurt to give it a good cleaning. I'm going to post up a zong mv28 cleaning/tuning how-to in the next couple weeks when I get some time.