mt stx 38 blows white smoke and it will die after 5 to 10 secs later what is the problem with is thanks, richard
The number that you didn't list after the STX-** will tell you the width.
stx 38 fly wheel
bladebelt diagram for john deere stx38 yellow deck
http://imgshack.info/images/k9bxsdwcte1kup0mijg6.jpg
get a new spark plug
Remove the deck from the tractor, then remove both blades. They can be sharpened using a grinder. If you don't have a grinder, then there are shops out there that can sharpen them for you (try asking at a shop that sharpens chainsaw chains).
10w40 for the engine and hy-gard for the transmission.
Check out crigby's John Deere deck page. It shows the belt routings for most of the JD mowers. See the link below.
From everything I see the 125 is a 42" mower with a 20HP engine. The STX-38 mowers were 38" with either a 12.5 or a 13HP engine. So, yes the 125 is bigger than the STX-38.
This depends on the condition of the mower and also what country you live in.
my stx38 currently has a FRAM PH3614 on it. hope that helps you =)
In Cincinnati, Ohio if it is good condition it would sell for around $400.00-$450.00