What are the symptoms I should be looking for? Kick-back✔, loud clunking noise on kick-back✔, starter not engaging after hitting the switch✔?
Kick back is usually related to where the pistons are relative to TDC when you push the starter button. Loud clunking noises are most likely caused by less than complete engagement of the starter gear possibly symptomatic of a bad bendix, bendix assemby, spring etc. The starter not engaging can be caused by the same issues. If you have a H-D with a 06 and older starter, you also have a starter drive shaft coupling which is an internal gear sleeve that can be causing the issues. Other than the clunking noise, none of the other things you mention would indicate a badly damaged ring gear. What you would most likely hear from that would be a gawd awful gnashing of gears, grinding, unholy nasty noise - - however, it could be intermittent. A well tuned H-D will often fire instantly which means the starter gear only engages a portion of the entire 360degrees of the ring gear. Unless you are near or on the bad teeth, you might not hear it. Bottom line ? If you're worried about this, drain your primary, pull the outer primary cover and check the gear yourself. With the bike in neutral and the battery disconnected, you should be able to roll the primary a full rotation to check every gear.
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