Craftsman 20 hp kohler garden tractor. Brand new starter and it spins but doesn't engage the motor...?

I had this brand new starter tested and shop says it is working fine... but when it is on the tractor it spins but the engine doesn't turn... ?? any ideas?|||if it is "whirring" over but not turning the engine over then 99% the ring gear on the flywheel has damaged teeth. If its a new starter was it not engaging properly before, coz this would mean the same - you could try turning the engine manually (with a screwdriver tip or summut) over just a fraction, then try starting it, coz it may then engage the teeth|||Maybe the starter Bendix isn't working properly. The little part on the starter shaft that comes out when the starter spins to engage the motor. They are easy to replace and cost less than $1 last time I bought one.


Hope this helps.|||When you hit the key, the spline gear on the starter should spin the gear on the engine. If this is happening, something else is wrong with the mower.