Small Engines (Lawn Mowers, etc.): Starter does not engage

Question
My John Deere 165 Lawn Mower with a Kawasaki engine Model FB460V (FB460223150)12.5 HP, the starter will not engage, and does not turn the engine over when turning the key to start (just clicks). I have to rotate the engine by hand many times, stopping at different positions because the starter just clicks until I rotate to a certain position that the starter engages and engine starts. Each time I rotate the engine several degrees, I turn the starter key to see if it will engage. In time I find the position that the starter will engage and then engine starts.
I installed a new starter with same results. Also I find that tapping the starter body helps to engage starter, but only if engine is in a certain rotation position. Engine is 25 years old, but runs great once started! Thanks for any suggestion, Jim

Answer
How old is the battery?  Have you dis-connected the battery cables and cleaned the battery cable ends and the battery terminals with a wirebrush?

Do you have a multimeter to measure voltage drop to check the condition of the battery cables and wires?  If not, I would buy one and save yourself some time and money.

You need to check the voltage drop across the cables to ensure they are still working well.  I have spent many dollars replacing parts until I learned about voltage drop and I have found bad cables...usually older ones like you have.

You can Google "How to measure voltage drop" and you will find many sites.  Here is a You Tube URL:

http://www.youtube.com/watch?v=9aioZN33xsA

http://www.fluke.com/fluke/uses/comunidad/fluke-news-plus/articlecategories/elec

Let me know if you have a multimenter.
Eric