Small Engines (Lawn Mowers, etc.)/Lawn Mower Engine


I need to replace the engine in my lawn mower but can not find one. Is there another one that will cross over for model# 331877-2371-G1. It is a Briggs and Stratton 540cc Platinum series 21 HP engine.

Many engines will fit by you may have to adapt the wiring harness, usually just the alternator connector, along with the throttle cable.  If you replace with another Briggs engine odds are the wire and throttle connections will plug right in.

Have you read the information at the URL below:

The crankshaft size on your engine will be a "standard" size but you will have to measure the diameter and length.  The engine footprint, aka mounting bolt holes, is an industry standard so most engines of similar horsepower will fit the mower with no modifications...just bolt on.

Let me know the size of your crankshaft and I can check on some engines.

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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