There is a nice Yellow Knob on the right hand side of steering wheel when you pull it out your PTO(Power Take Off) part that makes blades engage when hooked up right. To shut blades off just push know back in. Hopefully that helps and good luck with the mower. I have had mine 10 years it has never once had an issue.
1.9 Qts.
2461m
Turn your blades off.
I believe it is threaded into the transaxle at the rear of the mower
low viscosity Hy-Gard Transmission and Hydraulic Oil
Yes
It uses a 12 volt lawn mower engine battery.
what size nut is on the blades on a john deere z225 42 in mower
The regular deck on a 325 is 48" with three blades (You can only buy blades in sets of three from John Deere.) The standard blade is 16.6 inches in length.
This site has basic specs: http://www.tractordata.com/lawn-tractors/tractor-brands/johndeere/johndeere-lawn-tractors.html
Check your seat safety switch. Just a guess..
Yes, you don't need to do anything but remove the old ones and put the new blades on.