Small Engines (Lawn Mowers, etc.)/Briggs and Stratton v twin


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

Part list diagram link:

Check out this manual.

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

Link to the 273521 Briggs manaual:


Small Engines (Lawn Mowers, etc.)

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Eric A. Jones


Lawnmower Repair . Certified Master Service Technician from B&S. Have 23 years experience on B&S, Lawn Chief, Weed Eater, Echo, Peerless, Wheel Horse, Snapper, Atlas, MTD, McCulloch, Homelite and many other numerous brands. Specialize in electrical repair.


Born and raised in the midwest. Started tinkering with engines when I was about 14 on my Suzuki RM-80. I began lawn mower repair at a small hardware store. I knew absolutely nothing. I read lots of repair manuals and met an older fellow who taught me many lessons. I continued working on small engines through high school and paid my way through college working on mowers at the same hardware store. Decided to get away from the midwest and mower repair so I joined the Air Force. I repaired air traffic control electronic equipment and ended up in Hawaii where I got a part time job at Small Engine Clinic. I gained a lot of experience from the Small Engine Clinic and had a blast repairing small engines. I then took the Briggs and Stratton Master Service Technician test and earned my MST. I then traveled to Wisconsin where I attended the factory update training seminar and received formal training. Continued working on mowers part time as I completed 20 years of military. Retired from the military on a Friday and continued in the lawn and garden industry the next Monday.

MAS Aerospace Operations BA Mathematics AAS Electronic Communications AAS Electronic Technology

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