Behind the Door

A Briggs & Stratton WMI makes a nice weekend project


The finished Briggs & Stratton WMI.

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When June of 2006 arrived, I decided to spend a weekend completing a small engine for the summer show season, as I had not worked on an engine since the fall of 2005.

Most of my Briggs & Stratton engine collection is stored in my garage, with the larger ones kept at my son's shop. There was one, however, that rested behind the door to my wife's laundry room. I am not sure why I left it there; it just ended up there after I bought it on eBay from John Campbell of Norton, Ohio. I had covered the B&S in plastic and it was as complete as I remembered it in 2003 when I put it there.

I knew I had to work on a complete engine if I was going to finish the job during one weekend, so this was the one I chose. My tolerant wife was very happy to hear the news that my upcoming weekend project would be on the engine behind her laundry room door.

This particular engine was a Model WMI. The model is the industrial - hence the "I" - version of the popular washing machine engine that B&S built throughout the 1930s and into the 1940s. It has a deep oil sump base that incorporates an oil pump for heavy-duty lubrication. The original model WM had only a splash system for this purpose.

I had previously researched this engine and found it was a Type 20460 and serial no. 164227, which meant it was built in May 1938. It had a 1/2 HP rating and 2-by-1-1/2-inch bore and stroke. I also knew it had been used on a lawn mower, as it still had an original decal on the cylinder shield that read "Eclipse." As this decal was in fairly good shape, I decided to retain it as part of the little engine's history if it was possible.

The engine incorporated two starting methods, both a lever start on the drive side and a rope pull on the magneto side.

My weekend arrived and I woke early Saturday morning to get a good start on stripping down the WMI. It took me an hour and a half to take apart all the pieces and another three hours to clean and inspect them for wear or damage.

Everything looked good, so by noon, I was well into glass beading and painting all the parts that needed it. By dinner time, the painted parts were hanging on racks in the warm sun.

On Sunday morning, I applied a second coat of paint, and by noon I began to reassemble the parts. I added engine and air filter decals I obtained from CPC Reproductions of Rhode Island to the finished paint work. I preserved the original lawn mower decal by carefully cleaning and coating it with three layers of marine varnish. This process took longer due to the drying time for the varnish. So, although I finished reassembly of the WMI on the Sunday, technically the engine was not completely put together until later the following week.

The decal preservation turned out very well, so even though this engine was to be a weekend project, I felt the extra time spent preserving this piece of history was well worth it.

Unfortunately, the little engine never started when I gave it a try. It turned out the magneto was not functional and a replacement was required before it would run. But what a great way to spend a weekend! I would like to thank my wife for giving me the weekend free from the usual chores and for not complaining too much about the engine behind her laundry room door.

Contact engine enthusiast John Cox at: 2224 Wyandotte Drive, Oakville, ONT Canada L6L 2T5;