Are you sure this grease wasn't from installation? Grease is put on the axle before it is slid through the bearing.

When you put your finger in the bearing, and rotate it, does it feel anything but smooth?

 

Is this another case of "They all do that"?

 

Try these - Japanese used by PM. 6205-2NSE9.
https://www.nachi-fujikoshi.co.jp/en...pdf/B3402E.pdf

 

#6205? Hell that's the same bearing used on most all snowmobile idler wheels.
Can be bought for $5 most anywhere but the dealer, 3 times as much their.