What I'm supposed to do with this Chainsaw?
Solution 1:
Of course some Lucasarts humour:
The game featured some notorious red herrings, such as a chainsaw for which there was no fuel, despite many wishful rumours to the contrary. In one of the in-jokes that are a hallmark of the LucasArts adventure games, the second SCUMM game, Zak McKracken and the Alien Mindbenders, contains some fuel "for chainsaws only", but no chainsaws.
via wikipedia