Dodgy starter or gear ring I think,next time it clicks turn the key off put it in second gear push it a couple of feet then out of gear and try to start it on the key if it turns over in means the starter ring on the clutch housing or starter bendix is worn,most engines stop in one of two places so the starter gear always engages in the same spot,turning the engine a bit in gear means it engages on less worn teeth.The clunk n/s is because that is where the starter is,is it bolted up tight?
Rich t
December 2013