Hi Stuart, thanks for posting the pics....

What I propose to do here is tackle your problems in 2 parts.
The first part will be to get the prob with clutch and cylinder reel adjustment and chain tension corrected. To do this (and considering the good condition of the sprockets,) I believe the reel bearings may be shot, causing the snatching/grabbing you describe

The second part will be to hand you over to Grumpy (our Briggs guru) to get the engine sorted and running sweetly.

What I need you to do is:
(1) Remove the cylinder reel following the instructions contained HERE You don't have to remove the soleplate, we just want to make sure the reel bearings are serviceable. If in any doubt....replace them....(I would anyway, so I then know their history wink )

(2) Re-install the reel and adjust the cylinder reel to bedknife (bottom blade) clearance correctly. You will find the instructions for doing this is contained HERE
Once that has been completed, can you please let us know and we will proceed on to the clutch adjustment. grin
Just be patient and proceed carefully...any questions, please post to this thread. Best of luck!
cheers2


Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member.
Kindest Regards, Darryl grin