A sawmill includes a four-stroke internal combustion engine having an output shaft for driving a sawblade. The output shaft has a longitudinal axis. The engine is mounted on the sawmill for rotation between a first operative position with the longitudinal axis of the output shaft extending at a first angle, and a second operative position with the longitudinal axis of the output shaft extending at a second angle transversely to the first angle. The engine has fuel injection to facilitate operation in the first and second operative positions and a lubrication system incorporating a wet sump. An oil pick up for the lubrication system is configured to pick up oil from the wet sump at both the first and second operative positions.