working on a bear claw 110 Chinese 4 wheeler around 06 or 07. came in from a weekend mechanic with no spark all wiring unplugged dead battery. after a couple hours checking wiring and charging battery found no spark, so did what i usually do check fuse (ok) replace cdi new from parts bin, still no spark. now i checked the engine kill switch with ohm meter appears to work shorts to ground when in the no run position and open in run position. I than check coil measures ok but easy to bolt on new one just to eliminate it. still no spark. Check stator output and ignition output coil seemed ok but replaced with new again quick and eliminates it. still no spark aaaaahhhhhhhh replaced all the parts again, so far into this now the money is all gone now its how is more stubborn. still no spark. spent about 4 hours checking the wiring harness, connectors, fuse, anything i could think of
anyone have any ideas, my next step is to remove the kill wire out of the cdi and recheck for spark. but please any help will be greatly appreciated.

 

so how about the keyed ignition? did that check out ok? i presume you tried a new spark plug. did it have a rear tether kill switch towards the rear under the seat area?

 

+1 and check the connections they are sometimes very very shoddy soler joints? IDK why they just don't use connectors like everyone else cost I guess.

 

I did check the key switch seems ok I disassembled it and looks clean in side. There is no rear tether and seems no wiring to put one. spark plugs yes tried many and spark testers. when I had the wiring harness out I cleaned and tighten up all the connection. I have even checked for low oils sensor and nothing. I am missing something small but have over complicated it time to take a day away from it.
any ideas please let me no before the i put a big dent in the worlds alcohol supply.

 

i see no mention of checking a neutral safety switch or the saftery switch on the brake? I wold have pulled the kill switch lead out of the cdi long ago just to eliminate any of that.

 

well the brake interlock switch or the neutral switch should prevent it from cranking. i still wonder if a blade got pushed back inside a quick connect. if the keyed ignition and the red slider kill switch are ohming out good, then surely it ain't a bad CDI even though it was replaced. tried different spark plugs indicates it ain't a fouled/double grounded plug. WHOA! what kind of output are you getting at the coil wire outlet at the electrode? the slightly fragile coil wire could have an internal break between the coil and the electrode.

 

When you say you checked the stator output, how did you do that?

Your ATV has an AC CDI box that requires a hi-voltage pulse from the stator.
I have found stators packed with dirt, and bad hi-V pulser coil. They
are cheap, but you need a puller to get it off.

 

a bit of update removed the neutral switch, there are no brake switches, pulled the kill wire from cdi box and guess still no spark. I check stator output to the cdi box and I get a reading of 36 V ac. no reading out of the cdi box to the coil? I have read that I should see 50 to 200 volts? tried 2 more cdi boxes and another stator the same outcome. I hot wired it to eliminate the key with removed all lights. I know I am missing something simple. all the parts are working on other bikes from the show room. don't know

 

Do you have the common 6-pin CDI box? There needs to be TWO grounds
to it, both on the 4-pin section.

 

the cdi has one plug that has a 6 pin connector with 5 wires. stator feed, signal, ground, coil feed, kill switch. Ohms tested each wire swell as put a load through each wire to verify they will conduct current. I am just over looking something. how do you check or can you check cdi output to the coil? i get nothing on my dvom. tomorrow i might raid the show room and test a known running bike.