250x no spark, help please - ATVConnection.com ATV Enthusiast Community

suprant0010 · #1 (**permalink**) 09-28-2009, 03:02 PM

hi, i have a 250x...it was running fine for years, and then suddenly died, ever since it has had no spark...its a heavily modded atv, aftermarket hi-rev cdi box, has been working fine for years

ive changed just about every part trying to get it fixed:

2 new cdi boxes
tryed different alternator and pulse generator
tryed different coils and spark plug

i checked every wire on it, and did the factory test procedures for testing resistance on the alternator,pulse generator, reverse switch, and cdi harness...everything seems to be up to spec and still no spark

i disconnected the black/white wire from the cdi box, to make sure the igntion switch was not the issue, still nothing

is there some little detail im missing? im ripping my hair over this one, ive never been so stumped in my life

budedm · #2 (**permalink**) 09-28-2009, 03:48 PM

Now that is just bizarre. There just has to be a broken wire or fuse out somewhere. If your timing chain jumped, I think you'd still have spark, just at the wrong time, but not 100% sure about that.

suprant0010 · #3 (**permalink**) 09-28-2009, 06:02 PM

i have all the loom and tape ripped clean off the wires, i looked and tested just about everything looking for a break or faulty connection...there are no fuses in this atv that im aware of, just a resistor

the only conclusion i can come up with is the cdi box is not working...but im on the 3rd box now...i cant imagine they are all bad

this is AC based system is a bit confusing...looking at the wiring diagram, its hard to understand why they did some of the things they did...the inline resistor being one of them, not sure what the purpose of it is

another thing i havent touched yet is the AC regulator, i wouldnt know how to test it, or even if its critical to getting a spark

*its 1992 250x btw, im pretty sure the earlier models had different electrical systems

01 406ex · #4 (**permalink**) 09-28-2009, 11:58 PM

Check the voltage regulator/rectifier. They convert the electricity to make it spark.

suprant0010 · #5 (**permalink**) 09-29-2009, 12:52 AM

Quote:

Originally Posted by 01 406ex

Check the voltage regulator/rectifier. They convert the electricity to make it spark.

is there a way to test it? without actually swapping it out for another one

there wasnt anything about testing it in the photocopies of the factory repair manual i have