In this video a method is shown to remove the old and install new tappet guide bushings from a 2 cylinder engine.
The new bushings with an outer diameter of 24.97 mm have an interference fit with the crankcase.
After installation, the bushings ID needs to be reamed / honed to give a tappet clearance of 0.02 – 0.04 mm
Click this image to watch the video on Youtube:
