Trials & Tribulations: 5-Year Dempster Engine Restoration

An old Dempster engine avoids the scrap yard and comes back to life after an extended restoration.

| April/May 2018

The email note came unexpectedly in October 2012 from a nearby engine collector I’d never met. Randy Aldous had a Dempster Mill 1-1/2 hp engine he’d found on a farm in Aberdeen, Idaho, as a teenager and had hauled around for 55 years, never having had the money or time to restore it. He had read my story in the October/November 2012 Gas Engine Magazine, “A Farm Team Resurrected,” of the restoration of a 1917 Fairbanks-Morse Z and its companion Typhoon pump, and wanted to know if I would be interested in the engine.

A Vietnam veteran, Randy was at the tail end of life with advanced cancer, and didn’t want the old engine that had been a lifelong companion to go to the scrapyard after he died.

Well, of course I said yes and went down to see Randy and his engine. I was not familiar with Dempster engines, but I could immediately see this would be a challenging restoration! It had been sitting outside exposed to the elements for many years. Besides being heavily corroded and seized, many parts were missing. Yet I simply didn’t have the heart to say no, so I made arrangements to bring the sad old engine to my shop in Idaho Falls, Idaho. I learned later that Charles Randall “Randy” Aldous passed away only a month after our meeting.


The Dempster Mill Manufacturing Co. started in 1878 in Beatrice, Nebraska, making windmills and water-pumping farm equipment. Their first gasoline engines were 2-cycle models and were introduced around 1898. The 4-cycle engines were introduced after 1900 and looked similar to early Olds engines, with a vertical, box-like water hopper. Engines manufactured up to about 1922 were typically igniter fired using a right-hand mounted Webster Tri-Polar Oscillator magneto, after which they apparently went with the popular WICO magneto.

After more research, I confirmed this was a hit-and-miss, igniter-fired Dempster Model 1K, 1-1/2 hp engine, serial number 12897, manufactured about 1920. An exact date is unknown as there is no Dempster engine registry. Fortunately, this is one of the more common Dempster engines. I made an inventory of missing parts and sketched out a restoration strategy for this rusted engine remnant. I reached out to collectors from GEM, Smok Stak and HitNMiss to glean advice and develop sources for procuring missing pieces.

It quickly became evident that few of these well-built engines survived and finding parts would be difficult. The generosity within the old engine hobby for sharing information and the trust for providing original parts for re-casting was heart-warming. Over the next few years, original parts were generously shared by collectors, from which I cast and machined replacement pieces for my project including flywheel weights, the rocker arm and the rear crank casing.