QuadMan49

Good work Gw,

Did you weld the extended foot rests, or the previous owner? I'm thinking of doing something similar to my quad. The reason is because stock setup does not have much of a foot rest.

 Thanks for all the feedback!

Here's how the original CDI got blown: After riding several minutes the ATV suddenly stopped and quit running. I quickly found that the positive terminal on the battery broke off while riding from all the vibration of 20 years. (The engine was not running at this point)

After wedging it back on, the quad started up & ran fine, but due to the bumpy road the cable kept coming off, the engine dying each time. After doing this three times the 4 wheeler would only turn over, and as it turned out, it lost spark because the CDI got blown.

Hello everyone, it's been a while since I was here last. I finally found the correct used CDI on eBay for $315. After plugging it in, the 4-wheeler runs good again. Success! The only thing I don't understand is why the original CDI got burnt by connecting the battery terminal back 3 times while it was on. You would think it would blow a fuse first!

In my case, the CDI clearly got fried. Still looking for a replacement, any info on where to find a slightly cheaper one?

I'll try repairing the CDI. If that does not work, looks like my only option is to buy a overpriced new one.

1 Hour of chipping away, and my first gimps of the circuit board. it would be ten times faster without all those mixed in white plastic bits.  

I already tried one of those aftermarket CDIs with no luck.

4x4, The CDI should have 2 plugs: 1 with 6 pins, and the 2nd with 8 pins.

Keep us posted if the CDI works.

One of the connectors is slightly different on mine, so it's not compatible with my quad. Also one of the reviews says:

Reviewed in the United States 🇺🇸 on March 5, 2021

Ok.

Thanks for the help guys. I'll try repairing my OEM burnt CDI, if that does not work, I will halve buy a new OEM one.

Would a Kodiak 400 CDI work on a Big Bear 400? The connectors seem to be the same.

Regular synthetic Mobile-1. Works well in all small engines.

The photo makes it look like melted plastic but it's not. I removed some silicone/plastic material with a tool.

I use Mobile-1  10w-30 synthetic oil from Walmart in my equipment. It's $60 for a 12qt cardboard container, 10-40w is the same price.

44 minutes ago, Mech said:

 

After the repair you need to seal the board, it prevents parasitic leaks, and it stops the copper corroding..

That is, if I can ever get the CDI fixed.

Should I try some rubbing alcohol, or nail polish remover? Not sure if they will damage the circuit board.

Welcome!

I've  joined pretty recently as well.

Thanks everyone!

I'm in the process of chipping away at the silicone rubber stuff from the CDI, and it does smell like burnt electronics.

1 hour ago, Mech said:

Don't know mate, but I know Yamaha cdi, wiring, wiring colours, and switchgear come in about a zillion different flavors.. They are not as easy as most jap makes to figure or adapt parts to.

It would be a good idea I think to research what exact model and year and market you have before spending $300 or trying to buy a vauge as aftermarket.. The aftermarket guys will sell you anything..

Download all the 400 manuals you find in this site and compare their wiring diagram colours to your bike, then compare the plug shape and  pin positions they show compared to what you have.. 

To clarify, I bought my quad a year ago in excellent running condition. About a month ago the 4-wheeler bogged down while riding, I quickly discovered the positive battery terminal snapped off while riding. As soon as I put it back on temporarily, there was a spark and the quad would not run anymore. I looked at the CDI and several capacitors were popped out.

I tried a $25 aftermarket CDI, and not surprisingly it wouldn't even turn over. With the original CDI it would turn the motor .

Does that mean I'm stuck buying a $300 one? 

Hello,

Long story short, I accidentally fried my quad's CDI box.

I found several OEM ones for $300 which are out of my price range. Does any one know where to find one for less? Or any way to modify a $20 Chinese CDI to make it work? Thanks.