Can you use WD40 for chainsaw fuel oil?

No, WD-40 should not be used as a substitute for chainsaw fuel oil. While WD-40 is a lubricant and penetrant, it lacks the specific properties required for chainsaw operation, such as proper lubrication for the chain and bar. Using it could damage the chainsaw and lead to poor performance. It's best to use a dedicated chainsaw bar and chain oil for optimal results.