Small Engines (Lawn Mowers, etc.): Briggs and Stratton v twin, briggs and stratton, retainer ring

Question
I just replaced the governor on my Briggs model 407777 type 0121-E1. The engine uses a part# 793338 governor. I found out after I installed the case. That I installed the retainer ring in the wrong place. I looked for an hour for installation info before I installed it wrong. But found no info at the time. I installed it under the gear. I am not sure exactly how it is installed. But from what I understand now is that it should be installed on top of the gear. What I am unsure about is. Should it be installed right on top of the gear? Or does button that is mounted on top of the gear slip over the retainer? Also does this retainer have to be installed? I am just dreading having to pull the sump back off and having to locate another sump gasket.

Thank you
Phil

Answer
Part list diagram link:

https://www.partstree.com/parts/?lc=briggs_and_stratton&mn=407777-0121-E1&dn=29870003

Check out this manual.  
http://www.generac.com/PublicPDFs/C8221.pdf

It says Generac but it is a Briggs manual for your engine.



Link to the 273521 Briggs manaual:
http://dl.dropboxusercontent.com/u/12502267/B%26S%20Service%20Manuals/05_273521T

Eric