I am planning a top end rebuild on my 1980 ATC110,
Does anybody have ideas on a valve spring tool, preferably homemade methods or a purchased tool that will work on a 110??

 

Back before I had a proper c - clamp I used a regular wood type twist clamp with an open ended wrench sitting on the top on the valve spring. When the valve spring is compressed enough the keepers almost dismount automatically, getting them back in is a little bit harder.