I am having problems with my Scotts S1642 by JD. I need to repair the lift valves. Does anyone have the small engine diagrams? Thanks.

Hi.
If it is one with a Briggs engine, try the YouTube video at:
Lawn Mower Repair Valve Adjustment - YouTube (http://www.youtube.com/watch?v=NjzX-PUjKmo)
If Kohler, there is no adjustment as there are hydraulic lifters used.
Peace,
Clarke