2 PCS Idler Pulley Compatible with King Kutter RFM Series Finish Mower with Single Belt 4' 5' 6' Replace 164090

What It Is

This is a set of two idler pulleys designed to replace the OEM part 164090 on King Kutter RFM (Rear Finish Mower) series decks with a single-belt configuration. Idler pulleys guide and tension the mower deck belt, ensuring proper blade engagement and consistent cutting performance.

Fitment & Compatibility

Before purchasing, confirm your mower deck is a King Kutter RFM series with a single belt—not a dual-belt model. These pulleys fit 4-foot, 5-foot, and 6-foot RFM decks that use the OEM 164090 idler pulley. Measure the pulley diameter (typically 4 inches), the bearing bore size (usually 5/8 inch), and the overall thickness to match your existing pulley. Also verify the belt routing: single-belt RFM decks have one continuous belt driving all spindles. If your deck uses two separate belts, these pulleys will not fit. Check for any wear or damage on the pulley flange or bearing before installation.

Key Things to Know

• Quality: Aftermarket pulleys can vary in bearing quality. These have a 5.0 rating from only 3 reviews, so inspect the bearing smoothness and seal integrity before mounting.
• Installation: Typically a straightforward swap—remove the old pulley retaining bolt or clip, slide off the old pulley, and install the new one. No special tools required, but a socket set and a breaker bar may help if bolts are rusted.
• Common gotcha: The pulley flange must face the correct direction (usually outward from the deck) to align with the belt. Reversing it can cause belt misalignment and premature wear.
• Lifespan: Idler pulleys on finish mowers see constant heat and debris. Expect to replace them every 1-2 seasons depending on usage and mowing conditions.

Should You Buy It

If you own a single-belt King Kutter RFM finish mower (4’, 5’, or 6’) and need a direct replacement for OEM part 164090, this two-pack is a budget-friendly option for a simple DIY fix. However, with only three reviews, verify the bearing quality upon arrival—if you prefer proven reliability, consider OEM or a higher-reviewed aftermarket brand.