Okay I apologize in advance. I'm not much of a motor guy but I'm trying to learn. We bought our ATV a couple years ago but it's topped working after a few months. Would love to get this thing running by Christmas. ☺️ I've tried bunches of things but really not sure what to do now.

When I try to start it, the starter turns the motor but stops when it hits compression. If I take the spark plug out everything turns just fine. The battery is fully charged and I just try to brand new starter as well. I've even tried hooking it up to the battery from my riding lawn mower and does the same thing.

Any ideas? Thanks for helping this ignorant guy out.

 

Check earth and thick positive leads are tight. Try with the plug in but the plug lead off, if the ignition timing has slipped it will now keep turning over compression, indicating the slipped timing was making it fire too early and the piston would turn the engine backwards, while the starter was trying to turn it forwards. You will get a similar effect if the one way starter clutch is weak, it gives up just before TDC so engine stops turning. Either way, you need to check the one way clutch and that involves removing flywheel, if the flywheel key is sheared then ignition timing will be out. If that is OK check the springs in the one way clutch.

 

THANKS! I think this may be the issue. Anyone have a link to a tutorial for how to adjust the timing?

 

On most bikes you don't adjust spark timing, it is fixed by the key in the flywheel, but if the key shears timing goes out. I think on some Honda clones the backplate for magneto does move to adjust timing, but big marks on backplate and crankcase should line up if it is adjustable. Check those starter clutch springs while you have the flywheel off.