I've been trying different things for carrying a chain saw, and think I finally have it. I'm too cheap to spend $70+ to buy one and most carry the saw with the weight on the bar which I am not crazy about.
1 orange bucket from HD - $2.60
3 Left over TV mounting brackets - $0
2 U-bolts - ~$2, dunno - had a bunch in the garage
various bolts, nuts, washers
Mount one of the TV mounting brackets to the ATV with U-bolts.
Bolt other two TV mounting brackets to bucket - one on the inside and one on the outside. E.G. Sandwich the bucket wall to add strength.
Connect bucket assembly to TV mounting bracket on ATV with bolts and wing-nuts for easy-on, easy-off.
Cut hole in bottom of bucket for bar to go through. Use the chainsaw for perfect size hole
Cut out notch in top of bucket for chain-brake guard to rest in. This gets saw lower in bucket and also shifts load to saw frame.
You might want to bungee the saw in if you are riding really rough terrain.
Potential concern is how long bucket will last. But if it fails, it's only another $2.60 and I might look at stronger mount.