Briggs and Stratton 84004937 Maintenance Kit for 12.5-18 GHP Small Block V-Twin Engines

What It Is

This is a factory-recommended annual maintenance kit for Briggs & Stratton 12.5–18 Gross Horsepower (GHP) small block V-twin engines. It includes oil, filter, spark plugs, fuel stabilizer, and a foam pre-cleaner—everything needed for a single oil change and tune-up on residential riding mowers, zero-turns, and lawn tractors.

Fitment & Compatibility

• Engine models: Fits B&S Vanguard, Intek, and Professional Series small block V-twins (12.5–18 GHP). Check your engine’s model/type/code number stamped on the valve cover or blower housing.
• Deck size: Not deck-specific—works with any mower using these engines (typically 38–54 inch decks).
• OEM vs aftermarket: Genuine Briggs kit—all parts are OEM spec. No compatibility issues with aftermarket parts.
• Measurements: Kit includes two 20 oz bottles of 10W-30 oil (total 40 oz), one oil filter (492932S), two spark plugs (796112S, gap 0.030"), and one foam pre-cleaner. Confirm your engine uses this filter and plug type—older models may differ.

Key Things to Know

• Installation difficulty: Easy (oil change + plug swap). Basic hand tools needed—ratchet, spark plug socket, oil filter wrench, and a drain pan.
• Oil quantity: 40 oz total. Some engines require 44–48 oz—check your owner’s manual. If so, buy an extra quart of 10W-30.
• Fuel stabilizer: Included is a small 1 oz packet—enough for 2.5 gallons of fuel. For larger tanks or off-season storage, buy a full bottle.
• Gotcha: The pre-cleaner foam is for engines with an external foam sleeve. If your air filter is a paper cartridge only, this piece is spare—do not use it.

Should You Buy It

Buy this if you own a B&S small block V-twin (12.5–18 GHP) and want a convenient, OEM-matched yearly service kit. It saves time sourcing individual parts and ensures correct filter/plug specs. Not ideal if your engine needs different oil viscosity (e.g., 5W-30 in cold climates) or a larger oil capacity—you’ll need to supplement.