1920s Lawn Mower [Restoration] - Engine 

This machine was made by the Coldwell Lawn Mower Co. of Newburgh, NY, USA in the late 1920s. It claimed to cut and roll 3 acres on a single tank of gas using a 25" width reel mower powered by a 3.5HP Fuller and Johnson engine. It cost the equivalent of ~$7000 in current(2024) USD.
This video focuses solely on the restoration of the engine portion of this tool. The engine was not in the worst shape I have seen for something its age, but it is a very odd design and not common at all.
It fought me every single step of the way, to the point where it took me 4 months to fully restore.
I made some choices early in the restoration that came back to bite me in the end. I decided not to replace the piston rings despite a light honing of the cylinder, since replacements were not available at the time and I really didn't want to make new ones like I did for the steam engine restoration. I also decided to use composite cork with a gasoline resistant coating for the carburetor float replacement. Lastly, I decided to lightly repaint the outside of the of the magneto.
Unfortunately, all of these things were a terrible idea that set me back months of work and time. The piston rings did need a full replacement as compression was low and blow-by was showing up in the oilers. I found a single set in Australia. The coating on the cork float completely failed , so I tried coating it entirely in gasoline tank sealer, but that also failed. I ended up replacing the float entirely with one that I custom made out of nitrophyl, which is a plastic float resistant to gasoline. The original cork float was coating in shellac, which unfortunately will dissolve in modern gasoline, which contains ethanol. Lastly, I spent 5 weeks working on the Bosch BA-1 magneto, which decided to completely stop working after just painting the outside. This is a rare magneto with expensive and hard to find replacement parts, so I had to figure it all out myself. I ended up completely tearing the whole thing apart multiple times and investigating every part with my multimeter. Initially, it looked like the secondary coil needed to be rewound, which would have taking a professional several months, but once I got my hands on a more sensitive multimeter, it checked out fine. I also replaced the capacitor within the magneto, but that did not help either. After weeks of disassembly and reassembly, I found a hairline crack in one of the insulator parts that was allowing some voltage to leak and spark somewhere internally to the magneto.
I also chose to restore the radiator for the engine in the next part of this restoration, as I can run the engine for a short period without it, and this video was already running quite long.
In the end I learned that this is the first engine I've ever restored that has depression and truly hates all its original parts.
I'd like to thank @CRCAutoUS for sponsoring this video. I've switched to a food-grade penetrating oil from them as a more safe alternative, and it as worked just as well as the usual penetrating oils I've used.
You can check out the products from them used in this video in the links below:
www.evapo-rust...
www.crcindustr...
www.crcindustr...
www.crcindustr...
Wrenches, screwdrivers, and socket drivers are now for sale at www.handtoolre...
Watch narrated videos and help secure more tools for future videos (if you want):
/ handtoolrescue
Instagram:
/ handtoolrescue
Facebook Group - Share your restorations
/ handtoolrescue
/ handtoolrescue
Reddit - Share your restorations
/ handtoolrescue
Podcast (with @jimmydiresta and Andrew Alexander) - anchor.fm/fitzall