A bundle of surprises
Manufacturer: Briggs & Stratton Corp., Milwaukee, WI
Serial number: 1316
This is my 1926 Model FH Briggs & Stratton. It has a serial number of 1316, which means by serial number charts this engine was built sometime in March 1926.
The Model FH Briggs engine line was manufactured from 1925-1933. The engines had a 2-1/4-inch bore and stroke, and were rated by the factory at 1/2 HP at 1,800 RPM.
Worth the bid
This particular FH was found browsing eBay one evening. While I already had a 1930 FH, I decided it would be nice to have an earlier model with the obvious earlier engine features. I think these early engines look better than later models so I bid on the engine and won. I knew it was a unique and earlier model FH by its features and the factory-optional 1-gallon gas tank/engine base, but little did I know what it really was until the day the engine was delivered.
Then, I discovered the engine was one of the early-type low production 4-digit serial number models equipped with the very early version non-adjustable Type P FH model carburetor. This carburetor is said to be a carryover from the Model FE Briggs line that was only produced for one year in 1925 – the same year that began the production run for the FH engine line. Needless to say, I was thrilled because I’ve always wanted an earlier Briggs engine and this was finally the moment where I could say, “now I have one.”
The initial assessment
The engine was in usual shape for its age. It wasn’t too rough but it didn’t run and had seen better days. The governor spring clip was missing, the original starter cup was gone (I later made one from a Model B Briggs starter cup), and the original bronze governor spring was stretched almost beyond recognition. The throttle shaft also had 1/16-inch of wear in between the carburetor body and throttle shaft, and the ignition flywheel – made out of zinc alloy (also known as “pot metal”) – was so dried out it was buckled in and practically crumbled to the touch (I later replaced the flywheel with one from a 1930 FH). I also found that the gas tank was 3/8 full of dried gasoline, which was now a thick, cruddy coat of varnish-like substance, and there was also a 1/2 inch of old, black, greasy sludge in the oil pan. All of these things were signs of an engine that obviously hadn’t run in a number of years.
Running into surprises
As I began the restoration, I decided I just wanted to rebuild the engine and preserve what was left of the silver paint common to these early FH models. Like the carburetor, the silver paint was a carryover from the Model FE line and later FH models were simply painted black. To preserve the finish on my engine, I simply applied a coat of boiled linseed oil and a thin coat of motor oil on top of that.
About two days later, I started to take apart the engine, inspecting what was worn out, what wasn’t, and what needed to be fabricated. Surprisingly, I found that the main bearings of the engine – which are usually the first to wear out – didn’t have the slightest bit of wear on them. While this is good in the long run because it’s one less thing to repair, I knew that minimal wear on the bearings of an engine that old meant something else was wrong with it, and it was only a matter of time before I found out.
In the meantime, I cleaned the engine block and gas tank, and made the correct repairs to the carburetor and cylinder head. I also fabricated a new governor spring clip, carburetor choke tube and choke shutter mechanism, and ordered the other parts that I had no way of fabricating. Along the way, I found that sometime in this engine’s life, the cylinder had been bored to a measurement just shy of 2.275 inches – more than the 2.250 inches it was when it left the factory. I didn’t understand why, because the piston to cylinder clearance was perfect, so I proceeded to reassemble the engine. I used the same aluminum piston that came with the engine but replaced the rings with a standard set of rings from a later model FH.
A successful start-up?
Finally, after many years of being static and three weeks of work and repairs, I was ready to fire the engine. I put about 3/4 gas in the tank, filled the oil pan to the top with 20 weight engine oil, and spun the engine over a few times with the rope pull to prime the engine. This is an important step when starting an engine after rebuild to avoid what is called a “dry start,” which can result in bearing damage. I checked the spark one last time and checked the throttle plate position on the carburetor. Everything looked OK so I choked the carburetor and gave a fast but steady pull on the pull rope. The engine started on the very first pull! I was impressed because it’s not often that an engine starts that quickly after sitting static for so many years, especially after a fresh rebuild, but this engine did. Then I found out why the engine had minimal bearing wear. After not even 20 minutes of running, the engine started to act as if it was losing power and eventually started to die. I knew that was strange so I tried to spin it over to fire again, but the flywheel wouldn’t budge and the top of the engine smelled hot, and not your usual hot “break-in” type of smell either. I soon discovered the engine was binding up. The aluminum piston was getting too hot and swelling because of engine heat, causing a temporary lock up. After the engine cooled down, everything would run fine again.
Fixing an old problem
Later on, I discovered that sometime in this engine’s life, the cylinder was bored to accommodate a Model K Briggs piston. This explained the oversized 2.275-inch cylinder bore and the use of an aluminum piston. Obviously, it didn’t work, which explained why the engine had been sitting static for so long. It was simply someone’s experiment that didn’t work out.
In order to correct the problem, I had to track down a standard Model FH piston, which is made of cast iron. I then disassembled the engine and took the engine block to a local machine shop to have the cylinder bored and sleeved for the new piston.
About a month later, I picked it up and put everything back together. And later that same day, I prepped the engine just as I had for the first start-up attempt. I then proceeded to wrap the pull rope around the starter cup, choke the carburetor and give a swift pull on the starter rope.
Once again, it started on the first pull. With my fingers crossed, I continued to let the engine run for at least an hour while making slight adjustments to the governor spring tension, attempting to reach the proper RPM operating range, and the FH continued to run with no other mechanical issues.
To this day, even in the bitter cold winter months, with the use of the choke mechanism, the engine will fire and run on the first or second pull. Quite a feat for an engine that has been through so much and sat static for so many years. It’s a true testament to the way engines were built back then.
Contact Skylar B. King at 355 Woodrow Ave., Indianapolis, IN 46241 • email@example.com