The Briggs & Stratton Blues

A Briggs & Stratton Model FH meets Murphy's Law, but a Wisconsin engine restorer makes amends.

| January/February 2004

Briggs & Stratton Model

This little Briggs & Stratton Model FH is still an enigma for its owner and restorer. Ken found parts that presumably came from models FC, FB and FH.

Last spring, my friend Steve Anderson asked if I was interested in restoring a HP Briggs & Stratton Model FH. Since I've never been up-close and personal with one of these old 'vacuum pumps,' I readily agreed, thinking the restoration would make for a nice spring project. As a self-taught machinist (and I still have all of my fingers!), I've read a lot of books and asked a lot of questions. I have several home-built hit-and-miss and Sterling engine models under my belt, so when Steve asked me to restore this little Briggs & Stratton, it was an offer I couldn't refuse.

Getting to Work

The Model FH was mostly complete when I took it from Steve. A cursory exam revealed the exhaust valve pushrod and the choke tube were absent, and most of the threaded fasteners were loose. Upon disassembly, I found the oil pump plunger was missing, the gas tank was rust, and the carburetor's mounting flanges were broken.

Steve gave me the original operator's manual and parts list for reference, which claimed the Model FH was equipped with a four-bolt head. But curiously, this engine only has two head bolts, which seemed a little strange to me since the manual and engine should be consistent. I e-mailed Charles Camara of CPC Reproductions, who sells Briggs & Stratton parts, and he told me Briggs & Stratton often used spare castings from the factory on later models, and that the FH's crankcase probably came from a Model FC.

Unsure exactly what to make of this revelation, I happened to read on the Internet that early F series engines had the model and serial number stamped on the crankcase, while later FH models had this information on the brass tag affixed to the shroud. With that in mind I began cleaning up the crankcase, and sure enough I found the engine's serial number, FB3535, stamped there.

Internet information also indicated that early FHs used slanted cylinder fins and a bronze carburetor. This engine has the slanted fins, but the carburetor is made from pot metal. But that wasn't the full extent of things, as this engine also has a 3/16-inch-wide piston ring, and the oil pump plunger is operated directly from an eccentric on the crankshaft, not from a cam follower as my research indicated. These contradictions still perplex me, and make this engine seem as if it were some sort of mix between a Model FC, FB and FH. I like to think of it as a Model FH mutt.

Fix Her Up

After the age-old routine of degreasing and cleaning the FH's parts with a wire brush, serious restoration began with removing the rust from the base-mounted gas tank. Because the gas tank is nearly inaccessible, I found it impossible to scrape or wire brush all the surfaces, so I resolved to try the electrolysis cleaning process I had learned about on the Internet.