4 Pack 164090 Mower Idler Pulley Replacement Fit for King Kutter Fit for RFM Series 4'/5'/6' Belt Mowers – Durable, Smooth-Running Pulley

What It Is

This is a 4-pack of 164090 idler pulleys designed for King Kutter and compatible RFM (Rear Finish Mower) series belt mowers in 4’, 5’, and 6’ cutting widths. The pulley guides the belt under tension to keep the blade spindle spinning smoothly.

Fitment & Compatibility

Before buying, confirm your mower’s model and deck size. These pulleys are a direct replacement for King Kutter RFM series mowers with 4’, 5’, or 6’ decks—not for rotary cutters or finish mowers from other brands unless cross-referenced. Check the OEM part number: 164090. Measure your existing pulley’s outside diameter (likely 4 inches) and bore size (typically 1/2 inch or 5/8 inch). Verify the bearing type (sealed vs. greasable) matches your original. If your mower is not King Kutter, measure belt width and pulley groove depth to ensure fit. Aftermarket pulleys may vary slightly in thickness or flange design, so compare with your old part.

Key Things to Know

• Quality: These pulleys feature sealed bearings for smooth, maintenance-free operation. They’re durable but not heavy-duty; fine for homeowner or light commercial use.
• Installation: Easy to swap—remove the belt, unbolt the old pulley, and bolt the new one on. Use a torque wrench to avoid overtightening (typically 20-30 ft-lbs). No special tools needed.
• Common Gotchas: The 4-pack is cost-effective only if you need all four—check if your mower uses 2 or 4 pulleys. Some users report slight groove width variation; verify belt size (usually 1/2" or 5/8") before buying. Also, ensure the bore fits your spindle shaft—measure twice.
• Belt Tension: After installation, recheck belt tension. A new pulley can slightly alter alignment, causing belt squeal or slipping if not adjusted.

Should You Buy It

If you own a King Kutter RFM mower and need to replace worn or noisy idler pulleys, this 4-pack is a solid, budget-friendly choice. It’s best for routine maintenance on homeowner or light commercial decks. Avoid if you need OEM exact tolerances for heavy commercial use—aftermarket may vary slightly.