Just a note for future reference.
If you have a need or in the market for a valve compression tool for rebuilds etc. Like I have recently done.
The Clarke CHT461 OHC Valve Spring Compressor does not have enough reach to compress the spring to remove the collets.
I had to use some shims to get the extra depth.
Buy or borrow a different tool.
C.
From memory, one of these bad boys is up to the job:
http://www.machinemart.co.uk/shop/product/details/cht434-multi-valve-spring-compressor