Oregon 98-671 MTD, Sears, and Troy-Bilt G3 Replacement Lawn Mower Blade 17-7/8 in.,Black

What It Is

The Oregon 98-671 is a 17-7/8-inch G3 replacement blade designed for select MTD, Sears/Craftsman, and Troy-Bilt walk-behind mowers. It’s a medium-lift blade suited for general mulching and bagging on residential lawns.

Fitment & Compatibility

Critical checks before buying:

• Deck size: Fits mowers with a 17-7/8-inch blade length. Measure your current blade from tip to tip, or verify your deck’s listed blade size.
• Center hole: 5/8-inch round. Will not fit square or star-shaped arbors.
• Brand compatibility: OEM for many MTD, Troy-Bilt (including TB, TB230, TB240 series), and Craftsman models (e.g., 247, 374, 917 series). Not a universal fit—cross-reference your mower’s model number with Oregon’s online fitment chart.
• OEM vs aftermarket: This is an aftermarket blade, but Oregon is a trusted manufacturer. It’s a direct replacement for OEM part numbers 742-0690, 942-0690, and 742-04010.

To confirm: Find your mower’s model number (under seat or on deck sticker) and check Oregon’s compatibility list. If your blade has a different center hole shape or length, this won’t work.

Key Things to Know

• Installation difficulty: Straightforward—bolt-on replacement. Use a torque wrench to tighten to 30-35 ft-lbs. A blade removal tool or block of wood helps lock the blade during tightening.
• Quality: Oregon blades are heat-treated and coated for rust resistance. They hold an edge reasonably well but may dull faster than premium OEM blades on sandy or rocky lawns.
• Common gotchas: The G3 lift design is medium-lift—works fine for mulching and bagging, but may not discharge clippings as aggressively as a high-lift blade. Also, double-check that the 5/8-inch arbor hole matches your mower (most MTD/Troy-Bilt do, but some older models use a different size).
• Balancing: Always balance the new blade before installation. Oregon blades are usually close, but a quick check on a blade balancer prevents vibration and bearing wear.

Should You Buy It

Yes, if you own a compatible MTD, Craftsman, or Troy-Bilt mower with a 17-7/8-inch blade and want a reliable, affordable replacement. It’s great for routine mulching and bagging on standard lawns. Skip it if you need a high-lift blade for heavy wet grass or have a square-arbor mower.