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REO Runabout Engine Repair Questions

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The REO 552A engine, as used on 1949-1950 REO Model WD-21 teel-type mowers. The Photos were shared by Donald Kinsey in the April 2005 issue of GEM.

Justin Keffer writes in to add his name to our GEM Experts list, along with a question about a REO Runabout reel mower engine he recently purchased. Justin writes:

“I own ‘Professor Piston’s Small Engine Repair’ and specialize in vintage small gasoline engines of the kind used in weed eaters, tillers, lawn mowers, etc. Specifically, Tecumseh, Tecumseh-Lauson, Lauson, Jacobsen, West Bend, Clinton, Ohlsson & Rice, Briggs & Stratton, Pincor and Homelite.

“I’ve recently purchased a 1953 REO Runabout reel mower engine, which I am attempting to repair. It is a 4-cycle, and is slightly slanted to the left when viewed from the blower housing side. It runs clockwise when viewed from the PTO side. I have been unable to figure out what colors I should paint it, what its points ignition timing is, the spark plug gap, etc. If anyone can help me with these problems I would greatly appreciate it. I also need a color copy of this engine’s original decal. The nameplate, identification tag and other decals are missing. The engine appears to be the same shade of faded green. I also need the carburetor settings.”

“The carburetor is a Carter. I’d like to keep it original and not swap it for a Tillotson. I also need to know where I can get points and a condenser so I can get this engine running. I plan to build a cart for this engine and make a new wood starter handle with new rope.”

Justin Keffer, 800 Pleasant Grove Road Limestone, TN 37681


According to an article by Donald Kinsey in the April 2005 issue of GEM, REO engines of the type you own were built from 1949 through 1958, with some 20 different models produced. Going by the year and application, your engine should be a Model 404-G, although the flat gas tank you show in the drawing you sent suggests it might be a Model 211-G. For 1953 the engine was rated at 1-3/4 hp, with a bore of 2 inches and a stroke of, we believe, 1-3/4 inches. We’re not certain of the stroke as the period flier we found is somewhat illegible. However, with a rated displacement of 5.5 cubic inches, that should be correct. The Carter carburetor is correct, although we can’t tell you which model it should be. The spark plug should be a Champion J11 gapped at 0.025 inch. The points are supposed to be gapped at 0.020 inch with the timing set at 22-1/2 degrees before top dead center at a rated speed of 1,500rpm. As for the color, it should be a dull green, as you note. Perhaps a reader can tell you exactly what paint to use and, we hope, provide further information on the engine. – GEM

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