The chainsaw only spawns in farm loot.
As most of you know chainsaws require a mixed fuel, so you will not only need a jerry can but also some 2 cycle mix.
Once you have the jerry can and mix you can right click the 2 cycle mix oil and add it to the jerry can.
The jerry can will turn into a mixed fuel jerry can that has 5 fills in it.
Make sure your chainsaw is in your main hand. Right click the mixed fuel and select "fill chainsaw". Toolbox is required to fill your chainsaw
Once that is done hit the R key to start the chainsaw. You will now have 1000 ammo/fuel in the chainsaw.
2 cycle oil mix can be found in grocery stores, deer stands, and on hunter zombies.
If you log out the fuel that is in the chainsaw will leak out.
This is why you get 5 uses out of the mixed fuel jerry can.
- Available in 5 different colors!