Small Engines (Lawn Mowers, etc.): Craftsman mower trouble starting, amp fuse, starter clutch

Question
I have about a 12 year-old Craftsman mower with an 18 HP Kohler engine.  Mower wouldn't start.  Here is what I have replaced: 1) battery, 2) solenoid, 3) starter, 4) spark plug.  When trying to start it, it makes a whining noise below the key area.  The starter will not lift up and engage.  Seems like it is not getting power.  Not sure why.  Connections are clean.  20 amp fuse looks good.  I tried jumping the seat safety switch.  Not sure what else it could be.  Any ideas?  Appreciate it!

Answer
Hi Dan

Have you checked out the ground side of the electrical system ?   try jumper ground wire   back to battery negative

have you tried a battery jump lead  from battery  positive  direct to  starter motor terminal
if it cranks over and starts  then its electrical problem   

are you sure you hooked up the battery the correct way ?( have seen this happen ) starter would spin but not throw out  starter clutch  -

check heavy battery cables for volt drop   should be almost no volt drop or resistance
check power  from key switch to solenoid tab  - should be 12 volt d/c when key turned to start
check power  from ground side of solenoid back to negative  bat  terminal
check power accross heavy terminals of solenoid when key turned to start mode   
( should be full battery voltage )approx  13.5 volt  = full charge

check for faulty clutch/ brake switch ,, check seat switch  

if you can get make and model numbers  and any engine numbers off this machine  i will
endeavor to help  as much as can

let me know  

cheers  paul