Well last Saturday Sean Condon and myself replaced the keepers and retainers on my 750. The procedure was pretty interesting considering we never pulled the head and I thought I would share it with you . We used compressed air and a valve tool that connects to the valve springs, so if you need to put in new springs ,retainers ,keepers, or seals and do not want to pull the head this is the way to go. I used the fitting off my compression tester and a quick release for the air line and the valve spring compressor I purchased from JC whitney for $29.00. All we removed was the rocker arm assemblies, no need to disturb the cam itself. WEll thats about it.