Have an 03 650 prairie,left the key on,now it wont start.Turn the key on and everything is normal. Battery full charged,has real good spark,lots of gas,fuel pump works.good compression,reset valves,cranks real good but wont start. Has all the things to start but it wont.Could the cdi be bad.Took the plug off by the flywheel and the timing checks out.

 

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Ask the Editors: 650 Prairie Gone out to Pasture? - ATVConnection.com

 

A friend had an older Honda 300 that wouldn't start either. New coil fixed the problem on that quad.