[dumont19]

a couple of days ago i rode my 400 and noticed that it made a noise on the left side of the engine when i started it. it sounds like a really loud grinding noise, but goes away when i ride it and bring up the revs and will only come back it i start it again or have it idle for awhile. i took off the left case and was looking around the flywheel, there are some metal shavings and the gear behind it spins freely to the right but not to the left. any help would be great thanks.

 

[Here 2 help]

First thing that comes to my mind is............

The starter drive (similar to a Bendix on cars) is bolted to the back of the rotor (flywheel). The gear you see is part of the starter drive. It should turn freely counter clockwise and lock up when turned clockwise.

The metal shavings....... might be the bolts holding the starter drive to the rotor have loosened and are rubbing on something. Remove the rotor and check the bolts.

 

[dumont19]

why would it lock up if i spin counterclockwise and not when i spin it clock wise it is doing the opposite of what you said.

 

[Here 2 help]

I'm sorry, I described it wrong. It spins freely to the right and locks up to the left just as you described. It locks to the left so the starter motor turns the crankshaft. After the engine starts, the starter motor stops turning and the gear stops turning, but the crankshaft continues to spin.