I bought a 86 fourtrax that had been sitting for 5 years and I got it running and then it stopped had no fire so I put a new cdi box and then I had fire again until 3 days later I drove it parked it went back the next morning no fire everyone in awhile I can get a little spark could it be the cheap cdi or something else I can put the old cdi on it and put a test light on the black wire the goes to the coil and it will flash when the motor turns over :confused

 

Yes, a cheap Chinese CDI can fail inside a week from fitting. I had one do this on a Honda 300 recently. However when you fit a new CDI you must do the tests first, as you can blow the new one if something else is wrong. In the instructions we used to get with Dze CDIs it said that the CDI will blow if the earth lead isn't on properly. From experience, I have found an overcharging regulator can bow a new CDI too.

I suspect the 250 wiring will be similar to the 300 which shared the same basic engine design, so this is how to check the wires to a 300 CDI. The live lead to the CDI needs to be "live" with ign on. The earth needs to be negative, the wire from the neutral light needs to do something when neutral is selected, the ones from the alternator and trigger coil should pulse AC voltage when the engine is turned over. If all these check out, you could well have a faulty coil. If you do get it running, check the regulator isn't charging over 15v. If it is, get a new one.

 

I put the new cdi and it runs fine I'm guessing it was the cheap cdi I guess I'll see how this one goes

 

If you haven't done the tests, you may fry another CDI.

 

Exactly what ^^^^^^^^^^^^^^^^^^he says. When it comes to CDI's, one must verify everything else is good.....first. If you are familier with a digital volt/ohm meter, and have the manual ( or download ), this is not a really big task ( as long as the spark is not intermittant ). And as some one else mentioned, the cheap CDIs often fail...and quickly.

 

Is starter noisey when using? sounds like gears grinding or kick back noise? when these model get some wear and years on them the starting clutch one way bearing start slipping an cause reduction gear to sheer off an gear tooth an flywheel magnets can grab an broken tooth an chew the stator up....But if starting sound and works great....IMO I would do some test that has been mentioned before another cdi is bought

 

And, if the starter clutch is toast, and really dragging there can be too much voltage drop in the starting system for spark. Does it have a pull rope installed?