Small Engines (Lawn Mowers, etc.): Craftsman 19hp I/C Platinum Twin Cool, hydrostat

Question
I have a couple of questions regarding my mower.  The first is what type of spark plugs does it take.  The engine was a swap so hardly in of the info on the hood matches. The model # is 42A707, Type 162401 Code 9605215B. Also the transmission will not go in reverse.  You can move the lever but the mower just sits there.  The model # is 917.270940. Is this a diy job or something for the professionals? Thanks in advance

Answer
The plug is Champion number RJ19LM.  

For the transaxle, the first thing to do is make sure all the linkage is in place.  Have somebody work the shifter while you watch the motion.  If something's loose or not connected it will be evident.  The drive belt also has to have good tension.  The bracket on the input shaft for the shifter sometimes fails or the control rod fails, so look at that.  Those are the external things to check.  Internally it may be a check ball or what's called a variable swash plate.  Those would be the two likely problems.

I wouldn't recommend attempting a repair on the Hydro-stat without a manual.  You have to have all the proper measurements and you probably would need to go through the entire transaxle to determine the original cause of whatever failure occured.  Let me know if you have any questions.  Thanks, PK.