Small Engines (Lawn Mowers, etc.): troy bilt 18hp riding lawn mower

Question
Having trouble with starter. Crank up mower and the starter stay running after cranking. Cut off the switch and it still was running. So i disconnect battery. At one time i could just connect battery with switch off and starter would try to engage. Bought new starter still same problem.   Thanks Edward

Answer
Either you have a bad starter solenoid or a bad key switch.

Check You Tube:  

https://www.youtube.com/watch?v=MsvJMnpQBas

https://www.youtube.com/watch?v=oYHzIDnU3Rw

Is there a constant 12 volts going to the small solenoid wire (exciter wire)?
You should not have continuity on the high amp side (between the 2 big posts) when the key is in the run position.  Make sure you dis-connect the battery cable when test for continuity so you don't break your meter.

Test the key switch:

https://www.youtube.com/watch?v=q8G7kxCl9hY

This URL shows additional switches.
http://www4.briggsandstratton.com/miscpdfs/RNT/alternator_replacement.pdf
Page 23 covers 6 pole switches.

Let me know if the URLs help.
Eric