Quad bike with no spark

Rotor

Hi , I've got a chinese Loncin atv 110cc quad bike and can't get it running. It has no spark at the plug and i have changed the plug thinking it was that but still no spark.

so , working back from the plug it could be the coil or the cdi (correct?) (turns over fine and the battery is new)

How do i check what's faulty without buying stuff that turns out not to be the problem? and are the two things mentioned the only likely cause or is there other stuff it could be?

Thanks

BeenThroughItAll

Could be the coil, CDI, stator, pickup, possibly kill switch, or wiring.

Rotor

So is it a matter of getting a multimeter on each of the wiring junctions to see if there is a current and anything before the coil should be ~12v ?

twhitehousescat

the chinease stuff uses a simple ign switch , when off it joins 2 wires to "kill the engine , when "on" this connection is broken and the 2 power wires are connected , switches often fail and are very cheap

unplug the switch and check that first

Rotor

twhitehousescat wrote: »

the chinease stuff uses a simple ign switch , when off it joins 2 wires to "kill the engine , when "on" this connection is broken and the 2 power wires are connected , switches often fail and are very cheap

unplug the switch and check that first

Ok thanks - I'll give that a look in the morning

Rotor

BeenThroughItAll wrote: »

Could be the coil, CDI, stator, pickup, possibly kill switch, or wiring.

Where is the stator and what is the 'pick up'? thanks

twhitehousescat

stator, pickup, inside the engine , CDI is a "box" bolted to the frame ,

parts are well interchangable on those , the company that holds parts in the UK is china bikeparts online , as they wont list the quad you just need the engine type (left hand around base of barrel) 157fmi , etc etc the bits (cdi , will be for the engine not a specific bike

peter_the_piper

Can you give more details on chinabikeparts, can't find them on Google, not for me but BIL has a mower repair shop and sometimes gets asked about chinese atv's etc.

BeenThroughItAll

Rotor wrote: »

Where is the stator and what is the 'pick up'? thanks

The stator will be a fixed wheel at one end of the crankshaft, and the pickup is the Hall-effect sensor mounted to the crankcase that is used to generate the firing-order pulse to the CDI.

(Stator is the bit with coils on in this picture:
https://tboltusa.com/Tech_Data/uploads/images/how-to-remove-a-stator.jpg)

To be able to check the stator/pickup you'll need to 'scope the input to the CDI, or use a frequency measurement setting on a multimeter (most general purpose MMs won't have one, but it's often found on decent automotive meters).


ETA: Actually, the site above seems quite good for information on basic pit-bike stuff, which will be pretty much the same for your quad:


http://tboltusa.com/store/tech.php?pID=15/Home

Heliflyguy

Maybe some help with explanations and testing using a basic multi meter.

http://www.thumpertalk.com/index.php?app=core&module=search&do=search&fromMainBar=1