I have the engine from a qj 250 (edge 250 liguid cooled, same as older baja 250 I think) from pep boys in a racing mower. I had to ordered a new cdi cause it lost spark but in the mean time I tried to adapt a cdi from another china quad that was also a dc powered cdi into it. The cdi worked for a while but ended up burning up, so now the correct cdi is on the way but the problem is i removed the metal plugs from the plastic plug to switch cdi's now when I go to put the new cdi back in I don't know where the wires go. If somebody has one of these quads it would be great if you could take a picture of the plug showing what color wires go where it would be great if you could send it to my email which is rcpilot4@gmail.com.

Thanks,
Cole

 

1) What are the colors of the wires that go to your CDI?

2) Does your CDI look like this:

 

Unfortunately no, it looks like this, ill get the wire colors later today its 6 pin but only has 5 wires going to it all in one plug. Heres a picture of it from the place I ordered the new one. 250cc CDI Chinese 250cc ATV, Chinese 250cc Scooter, Chinese 250cc Quad, Chinese 250cc 4 Wheeler
Thanks for your help,
Cole

 

I looked at the picture of your CDI and now fully understand your problem. What pin is what...

I looked through all my wiring diagrams hoping to find a diagram for your style CDI (somtimes the wiring diagram draws the connector shaped like the real connector). I struck out. I did some searches on the internet and struck out there too. I probably just duplicated what you have already done before.

There is no way I can think of to probe the CDI itself to figure out what pin is what. The only thing left is to copy the wiring from someone else's quad. Let's hope someone with the same quad responds with a picture...

So you had this running on another style CDI (with adapted wiring). Was this the 6 pin 2 connector CDI like the picture posted earlier? When it ran did it run OK over the full range of operation (high speed, low speed, under load, etc.)? How long did it run before it died? Maybe it was just a bad CDI, and another good replacement would work fine?

 

Yes the cdi I used before was the 6 pin 4+2 like is in the picture you posted, I just did not use the kill wire and only had the power wire go to the coil not a power and ground from the cdi like mine was originally. I hooked it up per that wiring setup with all the pins adapted to the correct wiring and tested spark, it worked so I put the plug back in the engine. It started and idled for like 5-10 seconds before the box got hot and got a visible bulge in it and then I obviously lost spark again. I have posted questions on every thread where somebody has this type of atv and am waiting for a response with a picture. I agree that that is my only hope at this point. Thanks for all your help.

Cole

 

Best of luck getting the photo you need.

On the (2 and 4) 6 pin DC CDI that burned up: I think you just got a bad CDI. I suspect they test things (if they test them at all) by plugging them in to a test fixture and looking for spark fo a total of 1 second. It there is spark they ship it.

There are a lot of things that can be assembled wrong that would cause heat related failures over seconds to minutes after power up. Those type failures have been very common on this forum. Even worse, the assembly errors are duplicated through an entire batch which could be a very large number of units shipped to the same vendor.

So you might want to try this again (if your other CDI doesn't pan out), but if you try again get a CDI from another source. I don't think there is any design interface compatibility between the two CDIs that would cause a burn up. And it did start and idle, so you did have it wired right. The thing I worry about with a completely different CDI is whether the ignition timing is the same over the full engine speed. It might be, and it might not be. For two four stroke engines I would lean toward it being the same, but I really don't know. I know from experience that 4 stroke and 2 stroke CDI have a vastly different timing advance curve.