Subject: XR: Replacing valve stem seals and valve lash adjusters
I just did this to replace the springs, which is the same basic thing as replacing the seals.
Overview: Use a fitting in the cylinder connected to an air compressor to hold the valves "closed". I made a tool to pry the valve spring retainer down enabling the removal of the keepers.
Tools Required: The spark plug fitting is available from NAPA for about $5. This fitting also needs the air hose quick disconnect about $1. I made a lever out of a bar 3/16" x 1.25" x 24". I drilled a 1/2" hole about 1/4" from the end. I used several different thickness spacers (3/8, 1/2, etc) between the cam and the lever. I just remembered that I bent the bar about 6" from the end with the hole.
1. remove valve cover, remove spark plugs
2. turn motor to both #1 cam lobes UP, and piston at TDC
3. put in 5th and parking brake on hard and block wheels
4. put air fitting in #1
5. use spacer and pry the retainer down and remove keepers
6. remove retainer, spring, seal, replace
7. use spacer and pry retainer down and replace keepers
8. rotate until #3 lobes are up and #3 at TDC, repeat 4-7
9. repeat 4-8 for #4 and #2
Note: the first spring took me about 1/2 hour, the last 1 minute