Acts as if it is straining to start already changed one starter... had heard of a valve problem with these? Any input would be great love the mower and want to save it.

Yeah check your valve clearance,check both sides
1/4 " past top dead center
Set at .004 - .006
Luck

If you are a novice at small engine repair here is a video that explains it pretty well.

Here you go! (http://www.youtube.com/user/IFIXIT4U#p/u/3/hGkn0jR9RJM)