'03 Big Bear 400 4x4 - no spark / schematic
I'm just a casual rider and in the winter, my ATV is used for plowing snow. I'm the original owner and the winch for plow lifting is a Warn. Pretty sure the brushes are wearing on the winch as it makes a bit of a screech when used. I suspect this draws down my battery as I can hear the solenoid chatter when I first turn it over to start, but this goes away after it warms up, so I think it's charging. The battery is old, but takes a charge which will turn the engine over quickly without the solenoid noise.
After a big snow storm and hard work, it failed to start the next morning. I had just filled the gas tank. I opened the train screw on the carburetor and it's getting gas. I replaced the spark plug and after cranking over quite a bit, it failed to fire. I grounded the plug and saw no spark when I turned it over. I even held onto the plug to see if I could get a shock and couldn't.
Where do I start troubleshooting this problem? Is there a schematic that shows the parts used in ignition process from battery to plug? Always started easy. Are their points involved? Thanks for any help.