What is Timing chain slap exactly?
• If the check valve within the cam chain tensioner leaks/depressurizes when the bike sits for an extended period, the chain will loosen. No problem as long as it extends and tensions properly when running and there is oil pressure. The tensioner is easy to replace if it leaks too easily. People that remove it and scratch it, dirty it or crush it have had this problem. Inspect your left side plastic cam chain guide. If it is badly worn or chewed you will have chain stretching or lack of tensioner travel. When the timing chain stretches excessively, the plastic guides usually show wear first. The Tech Data chart in the Classic Service Manual (p11.8) gives: Timing Chain wear limit, distance from sealing face to chain tensioner piston: 9.5mm. Sure you can drop the chain off the bottom sprocket – no big deal, that’s what the crankshaft set screw is for, as long as the cam sprocket timing marks line up when you reassemble. Dropped it down several times – the only annoyance is when you drop
