As I had to replace the Drive Belt recently, and it was fresh in my head, I put the steps I needed to complete this job into AI and this is what it came up with.

I hope this will be of some use to someone.

P.S. these are the steps I needed to take, there may be an easier or harder way to do this.

Diagram Orientation

• See diagram attached.
• Diagram is viewed from underneath the mower looking upward.

https://preview.redd.it/aci5k76ow42h1.png?width=1536&format=png&auto=webp&s=ab87dc42da9ecaf33c11e477640a26ba50ba5739

Tools Required

• Socket set
  • 13mm socket
  • 14mm socket
  • 15mm socket
• Long screwdriver
  • Useful for guiding the belt into position around pulleys
• Long-handled tension spring puller
  • For removing/refitting the tensioner spring

Access Required

To gain access to the drive belt, the following components need to be removed:

• Remove the deck belt from around the drive shaft pulley.
• Disconnect the small electrical wire connector:
  • Push the retaining clip upward first.
  • The connector can then be removed easily without forcing it.
• Remove the mounting plate with the two long screws into the chassis:
  • This plate must be removed to route the belt correctly.

Pulley Layout

The drive system consists of:

• 3 main pulleys
  • Left drive pulley
  • Engine / drive shaft pulley
  • Right drive pulley
• 1 jockey / idler pulley (J)
• 1 tensioner pulley (T)

The jockey pulley and tensioner pulley are connected by a solid arm.

The tensioner spring connects from beside the tensioner pulley down to the chassis.

Installation Tips

• Route the belt around the 3 main pulleys first.
• Leave the tensioner pulley route until last to make installation easier.
• The jockey/idler pulley can be loosened or removed temporarily to help fit the belt.
• Reinstall and tighten the jockey pulley once routing is complete.
• If the belt feels loose after installation, the routing is likely incorrect.
• Even with the tensioner loose, the belt should still feel fairly tight.

Final Checks

• Ensure the tension spring is fitted correctly.
• Verify the belt is fully seated in all pulley grooves.
• Check that the belt is not twisted anywhere.
• Ensure the belt runs correctly around both the tensioner pulley and jockey pulley before applying tension.