Fourwheeler is turning over but will not fire

Do you have fire at the spark plug. If so check compression, then if not check fuel system(( carb)

if turn over no spark check battery,plug , plug wire , wiring and cdi if no turn over check battery , fuse,switch,cut out switch

First things first, check you are getting a good spark by removing the spark plug and with it attached to the coil hold the body of the plug against the engine and crank it over, you should see a nice blue spark over the plug gap. If not make sure you have power getting to your coil, if good try another plug, then if not, try another lead, then if not, try another coil. Also check that the kill switch has not open/short circuited. There are a number of things that could be causing the grief but I hope these couple of pointers help.

It may be too simple but I have to ask, are you using a known good sparkplug, high tension lead and plug cap? Next is either the source coil isn't providing power to the "Black Box" or the pickup coil isn't sending a signal to the box to fire the sparkplug or finally the box itself is defective. To test further you will need a Shop Manual or Clymers manual and a VOM (Volt-Ohm Meter).

suspect a kill switch turned off, then a safety harness switch and then a cdi box...

4 wire or 5 wire cdi makes a difference.? help me help you !!

check fuses to coil,all switches on ? will crank w/o fire if switches are not all on! remove boot from end of plug wire and w/well insulated pliers hold wire slightly away from eng or good ground of any kind on atv.turn eng over should spark blue and look hot. (snapping sound ) can be heard. if not the problem other componets can be tested but need knowledge of wiring. componets and able to use multi volt meter

Have you checked the Spark Plug ? No Spark & No Fuel means not going to start and run. If you are getting fuel then your Spark plug may need to be cleaned or replaced or even re-gaped. Spark plugs have a tendency to get fouled out. Meaning oil gets on it and it can not throw a good spark. If you do have a good spark then check the choke and or the float in the carb.

Thanks for allowing my in-put!

check supp lie electricity to coil, if ok. but no spark. check ur ignite r in ur cdi box

johnnymleder, Remove sparkplug from engine. reconnect sparkplug to sparkplug wire. Make sure sparkplug is in contact with engine cylinder head. If you don't see a spark when cranking engine over( in dark garage at night) then something will be wrong with the motor's ignition system and will require servicing it to restore operation. If you see spark then reinstall plug into the engine. Do NOT connect ignition wire!!! Crank engine for 15-25 seconds. Do you smell RAW GASOLINE at the tailpipe??? If NO you may have clogged fuel system. Have FIRE extinguisher handy at ALL times when performing work on any fuel system!!!! Good luck with repair!! 12fixlouie