Thanks for the quick response.
The serial number of the mower is 471179. The parts list gives the number as 004298 - it's the same number in the list you have on this forum for both old and new Morrisons.
The part I obtained from Supplier was described as Genuine Masport Sprocket Assembly-10/23 Lh Thread Rm 004298, 032006.
The machine has a 1989 Briggs and Stratton 3hp engine so I assume it was built sometime after then.
Am away from home but when I get back will post photos and try to measure the pitch of the thread on the reel/cylinder shaft.
Thanks again.
I have attached the dealer notification regarding the sprocket and spoken to the technical guys regarding your problem. They have stated that the thread has never changed since the start (thread could have been damaged on shaft when removing old sprocket as new one would have no damage) and the only change is when they moved to a keyed sprocket.
Note that the threaded sprocket was discontinued back in 2012 and is no longer available for purchase through them and the suggestion is to replace the cylinder to the later model.
I would also be assuming that they sent you the correct sprocket as it would have been sitting on the shelve for over 5 years.
![[Linked Image]](https://www.outdoorking-forum.com.au/forum/images/members/mower-monsterw.jpg)
