i have a tao tao 250 that wont spark im only getting a pulse off of the red and black wire on the magneto that goes to the CDI ive tried looking for a wiring diagram with no luck if someone could heip or tell me what to test i have a good multi meter

 

Does this look like your CDI?



If so, the first thing to do do is eliminate kill switch issues:

Unplug the CDI, and use your meter to measure the kill switch pin resistance in the wiring harness to ground. When you do this make sure all kill switches are "off" (handlebar, tether), and the ignition switch is turned "on". You should measure an open circuit (infinite ohms).

When you turn off the ignition switch it should measure zero ohms to ground.

What do you see?

The next step is to measure the stator ignition power voltage, and the ignition timing trigger voltage. But do the kill switch tests first.

 

i keep poping the fuse whit the key switch hooked up? how many saftey switchs are tere one on the fornt break and one on the rear is that it

 

Certainly you need to figure out the fuse popping problem before looking at why you aren't getting spark.

What do you mean when you say the fuse pops when the ignition switch is hooked up. Does that mean this happens when you plug the ignition switch connector into the harness? Or does it mean you pop the fuse whenever you turn the ignition switch on?

What is the history of this quad? Has it been rewired recently? Is this a "problem" quad bought off someone for cheap? Have you ever seen it running?

As far as CDI's causing this (via your PM) the answer is maybe, but only if you have DC powered CDI, and even then it is unlikely. But you can verify this by unplugging the CDI. If the fuse popping stops then you have your answer. If you have an AC powered CDI then it has nothing to do with blowing fuses.

You never answered my question about whether your CDI looks like the one in the earlier picture. The best way I can help you is to have as much info as possible to work with. That means you have to give me that info or I'm just shooting in the dark.

About the safety switches:

1) The brake switch is there to keep you from turning the starter motor unless the brake switch is on (in other words the brake light is on). It most likely has nothing to do with blowing fuses unless the fuse blows only when you apply the brakes with the ignition on, or if there is a short to ground right at the brake switch itself.

2) The "one on the rear" I assume is a tether cord kill switch. That safety switch kills spark and shuts down the engine when pulled off. It has nothing to do with blowing fuses, or keeping the start from turning.

 

yea thats my cdi and if its just pluged in it will pop it ive checked all the wires i have one that runs so ive been going back and forth but i dont want to mess it up i just browed it to look at
and i also have a 50cc baja that the head was off and i was wondering if the piston should be top dead with the valves closed or where should the piston be with them closed

 

If I understand your post correctly if you unplug your CDI the fuse blowing stops? In other words, you unplug the CDI, put in a good fuse, turn on the ignition switch and the headlights work?

But with the CDI installed the fuse blows *only* when you turn on the ignition?