Last time I had started building the engine and had most of the bottom-end components in place.
I had fitted a new primary drive chain, as it seems logical to do this when the engine is apart. But I thought: ‘What if I wanted to know if it was worn or not? How long do they last before they are worn out?’ A quick internet search gives a rough figure of 60,000 miles and the Honda manual gives a measurement of 129.78/129.98mm between the outside of the shafts, which makes no sense. But, it implies that a chain is worn when 1.3 to 1.1mm longer than a new one.
