394018S Air Filter for MTD & Toro 394018, Briggs Stratton 392642 271271 272490 5050 and John Deere LG394018JD GT235 LT166 LTR166 LT170 LX288 SST16 SST18 1200 Hydro Rake Lawn Mower Parts

What It Is

This is a replacement foam pre-filter and paper air filter element for Briggs & Stratton, MTD, Toro, and John Deere lawn tractors and zero-turn mowers. It fits engines using the 394018S, 392642, 271271, 272490, or 5050 filter cross-references, commonly found on 12–25 hp single-cylinder and V-twin engines in riding mowers, garden tractors, and commercial stand-ons.

Fitment & Compatibility

Before buying, confirm three things:

• OEM part numbers: Directly replaces MTD 394018, MTD 394018S, Toro 394018S, Briggs & Stratton 392642, 271271, 272490, 5050, and John Deere LG394018JD. If your machine uses any of these, it’s a match.
• Engine series: Fits most Briggs & Stratton single-cylinder (Intek, Endurance) and V-twin (Vanguard, Professional Series) engines found on models like John Deere GT235, LT166, LTR166, LT170, LX288, SST16, SST18, and Toro 1200 Hydro Rake. It does not fit OHV or opposed-twin engines with different filter housings.
• Physical size: The paper element is roughly 4.5" x 3.5" x 1.5" (L x W x H). Measure your old filter or the housing opening—if it’s significantly larger or smaller, it won’t seal.

Check your model’s engine deck size (e.g., 42", 48") only to confirm the tractor chassis—filter compatibility is purely by engine, not deck width.

Key Things to Know

• Quality: This is an OEM Toro-branded filter, not a generic aftermarket. Foam pre-filter is oiled from the factory—do not wash or re-oil; replace it.
• Installation: Takes 2–5 minutes. Remove the old filter, clean the housing with a rag, drop in the new paper element, then slide the foam pre-filter over it. No tools needed.
• Common gotcha: Some users report the foam pre-filter can be slightly tight on the paper element—just stretch it gently. Also, if your engine has a separate foam-only filter (no paper), this kit won’t work; you need a standalone foam filter.
• Frequency: Replace every 100 hours or annually, whichever comes first. Clean the housing every time to prevent debris bypass.

Should You Buy It

If your MTD, Toro, or John Deere lawn tractor uses one of the listed OEM filter numbers and you want a reliable, drop-in replacement at a fair price, this is a solid choice. It’s slightly more expensive than generic brands but built to factory specs, so you avoid air leaks or poor filtration. Skip it only if you need a pure foam filter or a different part number.