Hi all, I'm no mechanic but have just had my shogun sport 05 come back out of the garage for the 2nd time in a month after a troubled bottom pulley, problem is I think the issue is not sorted as my engine is tapping like its timings are wrong. My mechanic has assured me the crankshaft shows a little damage but not enough to pull the pulley off so why has it come off again? Has had new bolt and but and pulley and has been tightened to 185n which he says is correct. Any ideas would really help

did they use thread lock is the wodruff key ok