Half-(baked) Restoration

Breathing Life into a Briggs Modely

| October/November 2001

  • Briggs & Stratton Engine

  • Briggs & Stratton Engine
    Kick start side view of Jim Davis' Type 60521, Model Y Briggs & Stratton.

  • Briggs & Stratton Engine
  • Briggs & Stratton Engine

My collection of small gasoline engines has languished for some time without anything being accomplished in restoration. Recently, a new addition to the engine group sparked a rash of skinned knuckles, sandpaper, and paint spray cans.

I have plenty of the usual hand tools and wrenches, but other tools are limited to a 3/8-inch electric drill with flexible shaft, bench grinder with wire brush, dremel tool, small tap and die set, and a couple of small gear pullers. Fortunately for me, the newest member of my engine family lent itself to a restoration that is possible with a limited tool arsenal.

The engine is a Briggs & Stratton Type 60512, Model Y (s/n 208238) with kick pedal start, and could have been the poster boy for 'rust bucket.' Everything was still there except the gas tank, pedal return spring and pedal rubber bumpers. The suction gas line was still attached, although wound up in a tangled ball. Even though the engine was stuck, I figured I could surely free-up a small, 1-cylinder engine. What really attracted me was the little suction carburetor, which turned out to be stuck.

For those not familiar with the Model 'Y' carburetor, it has a 5/8-inch diameter air intake with a tiny butterfly valve choke. The throttle valve is what I would call a spool valve, not a butterfly. It's brass, and slides horizontally when actuated by the air vane governor to control intake air flow. In my limited experience, I had not seen one before. With some TLC, I was able to free up the carburetor, including the stuck choke butterfly, without breaking anything.

The Model 'Y' had been sitting in a garage corner on a dirt floor, so there was plenty of corrosion on the base parts. There was some pitting on the lower part of the flywheel air shroud and one very small spot had rusted through on the lower edge. It was easily repaired with auto body repair putty. As I mentioned earlier, the engine wouldn't turn when found, but when the air shroud was removed and all the accumulated grit, crud and dirt dauber's nests were removed, the engine turned freely. Miracle of miracles, the thing had some compression!

Based on the rotation and compression being there, I started what was to be a half-(baked) restoration, I guess, since I never removed the head. The crankcase bottom plate was removed for internal cleaning of minor sediment accumulation and external cleaning of rust and corrosion. The inside of the engine was oily and surprisingly clean. There was no excess rod bearing clearance, and the piston and pin did not appear to have slop when the crank moved. The side plate, with the magneto and one of the sleeve bearing mains, was removed and this allowed further inspection of the crankcase interior. It still looked good internally, and the main bearing looked fine.

Hoping the magneto would work I cleaned and adjusted the points, and reinstalled the side plate after de-rusting all the other parts, reassembling and repainting them. I hand-cut a gasket for the magneto side plate to the crank case joint. The crank case bottom plate gasket was left intact, but sealer was added. The hardest job of all was removing the belt pulley from the crank shaft.

With the help of my son, Mark, and his bandsaw, a red oak carrier/skid was fabricated. Brass bolts were used on the engine shroud and brass acorn nuts were used on the engine hold-down bolts. An oil drain was made of 3/8-inch brass pipe to clear a cross piece of the skid. The brass serial number plate was cleaned and reinstalled. The original Briggs & Stratton decal was cleaned (as much as possible) masked during painting, and then coated with polyurethane for protection.

Carburetor of Jim Davis' Model Y Briggs & Stratton featuring a 'spool' throttle valve instead of the more common butterfly valve

The copper suction gas line was untangled carefully and cleaned. A suction type gas tank was added and painted red after soldering a new screen on the suction tube. A faucet aerator screen was found to be the exact size of the carburetor intake, and was held in place by a 5/8-inch diameter chair leg plastic tip with the end cut out to leave a tiny edge to hold the screen in place. I don't know if it ever had any air intake protection when new. The original choke cable bracket was there and I made a choke control from a brass plumbing ferule, clamped in the bracket as a guide, and a wire with rubber grommet as a handle.

Rubber bumpers for the kick pedal were fabricated from rubber stoppers, cut down in thickness, and with recessed bolt holes for mounting. Three trips were required to ACE Hardware to get the proper tension pedal return spring.

What a thrill when I finally got the first hit from the engine! It was only then I knew the magneto was okay. Several tries later, amid frantic carburetor adjustments, and with oily carbon chunks flying from the exhaust, the engine began to settle in, and the longer it ran the better it ran. It now starts on one or two kicks and runs fine.

As mentioned earlier, I call it my half-(baked) engine restoration, since the head was never removed, no valves were ground and no internal mechanical work was done. I had a ball working on it. People ask what I'm going to do with it. Will I sell it?

I tell them they missed the whole point. Working on it, making it run and look good, is the reward in itself.

Engine enthusiast Jim Davis can be contacted at 21 Foresters Lane, Springfield, IL 62704


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