Hello there. M900 Refurb

So it,s been a while due to injury, Christmas etc, but a quick update.
I took the belts off to see how things looked as I was convincved something was rubbing, causing the slow engine turn over. When I took the bottom pulley off I discovered that the (new) circlip had failed and the pulley had pushed the woodruff key out and smeared the oil seal behind it. I'm perplexed as to why this might happen but I have replaced all the parts and put it back together. Hopefully this will sort it out. I'll let you know how it goes...