I recently purchased a toa toa 110cc atv. Its A 2007. When i go to crank the motor the sarter will stop cranking when it comes up on compression stroke. It acted like the starter was bad. So i bought a new battery and starter for it. I put the new starter on and same problem. I then jumped 12v from the battery straight to the starter positive and ground, same problem persists. I`m scared that the motor may have somthing wrong internally. I crank the engine via flywheel by hand with out to much effort.
I put a compression gauge on the motor and was able to crank it with a ratchet on the flywheel nut. I got a reading of 100 lbs. I bought the new starter off ebay.....Is it possible I have two bad starters? They both spin freely when not attached to the ``cranking chain''. Any help would be GREATLY APPREICIATED!!! The starters will crank the engine when i take out the spark plug to relieve compression.Batteries were fully charged. Also tried a 12v car battery with same problem.

 

I can't see anything wrong with your thinking or your procedure. You are doing exactly everything I would be doing.

When you jump the car battery directly to the starter motor input post, where did you put the negative half of the jumper cables? Was it directly to the starter motor, or the battery negative post? Jumping directly to the starter motor eliminates bad connections on the return wire from the engine to the battery negative terminal.

Also try measuring the voltage right at the starter motor with a meter while your starter motor is stalled on the quad compression stroke. Be sure to jump straight to the starter motor input post, and straight to the starter motor frame on the negative side. It should be 11 volts or higher. If you get this voltage then your problem is a bad starter or an engine that is too hard to turn. If the voltage is low then your jumper cables aren't making a good enough connection.

A while ago there was someone who had very similar symptoms on a 250cc machine (engine turns easy with a wrench, multiple starters didn't turn). He eventually found a mechanical problem in the starter gear path to the engine. Under torque from the starter something shifted and got bound up with something else. But without torque from the starter the parts would wobble past on another. Obviously this doesn't apply to your engine, but its an idea to keep in mind.

 

I`m wondering what might cause the engine to not crank freely. Any helpful suggestions on that would be appreciated. I dont really want to buy another starter just to rule that out. Is there any way to tell if a 110cc starter for a honda clone is good?

 

I would definately check the voltage at the starter to make sure that isn't the problem. Then I don't know. Dragging clutch? This is a strange problem.