Hello, i picked up a 1991 quadrunner 250 4x4. My question is, when i hit the starter button, i can hear the starter turning but the engine doesnt. I can pull start the engine fine. I removed the starter and tested it. It spins fine. When i put it back in and tried it it just spins. So i pulled the left side engine cover to look at the starter clutch behind the flywheel. I havent removed the flywheel yet becuase i need to get a puller, but does that sound like a bad one way starter clutch bearing? Also when i removed the spark plug and hit the starter, the piston goes up and down but as soon as you plug the hole to make compression, it stops going up and down and you can just here the starter spinning again. Could the starter be bad even though it spins just fine when testing it? Has anyone encountered this?

Thanks

 

With the cover off, I would remove the plug wire (so not to start the engine) and hit the starter button to see if the starter is engaging the flywheel and if it is turning it. You might be hearing the starter hum but not turning when under a load.