94 timberwolf starter does not engage engine

I have a 1994 Yamaha Timberwolf that has been a strong running machine until recently. This past year I replaced the pulsar coil which resolved a prior problem I was having. After running for several weeks without a hitch, I one day went out to start it and it would not. The starter motor is turning but it does not engage the engine. Can anyone suggest a remedy to get it running again?

I have gone over the whole electrical system while in the process of correcting the pulsar coil problem. I believe where I hear the starter motor turning the problem lies elsewhere; I think.