Small Engines (Lawn Mowers, etc.): Kohler 12 hp - slow crank, fly wheel, strator

Question
Hard time turning over...Put a new battery in it and it is still doing the same thing.  When I take the plug out it turns over very nicely.  

I think I need a battery with more CCA?  I am thinking over 400...I am not sure how many the one I recently bought is...I bought it at sears.

I took the flywheel off recently to change the strator...It ended up being a loose wire...I left the old strator on.  Is it possible that I messed up the timing because I removed the flywheel and am now getting kickback?

Last question...I did not know what kind of oil it took so I put a synthetic oil in it...something like 20w 50.  Something very thick.  What do you think?

Thank you,
Michael  

Answer
#1 fly wheel is on a keyway slot, no way  of messing up timing on kohler that is done by points, etc.  if its the older starter generator style? could be that is weak. a heavier cca battery may do.   as for #2   remove that oil...   10w30  or straight 30  oil only.