725-04439 Starter Solenoid Relay for Lawn Mower, 12V Relay Switch, Fit for Cub Cadet/John Deere/MTD Lawn Tractor, Replace AM133094, 435-151, AM138068, 816-1211-211-16

What It Is

This 12V starter solenoid relay delivers battery power to the starter motor when you turn the key. It’s designed for lawn tractors from Cub Cadet, John Deere, MTD, and similar brands that use a standard three-post, push-on terminal solenoid.

Fitment & Compatibility

Before buying, confirm three things:

• Terminal layout – This solenoid has two large studs (battery and starter) and one small spade terminal (trigger). Measure the center-to-center distance between the large studs; they should be roughly 1.75 inches apart.
• Mounting holes – The mounting bracket uses two holes spaced about 2.5 inches apart. Verify your existing bracket matches.
• OEM cross-references – Replaces AM133094, 435-151, AM138068, and 816-1211-211-16. If your tractor uses any of these part numbers, it’s a direct swap.
• Voltage – Must be 12V (most lawn tractors are). Not for 6V systems or zero-turn mowers with different solenoid designs.

Check your old solenoid’s physical dimensions (roughly 2.5 x 2 x 2 inches) and that the spade terminal is the same width (typically 0.25 inch). If your tractor has a four-post solenoid with an additional ground or ignition terminal, this won’t work.

Key Things to Know

• Quality – At $12.99, this is a budget aftermarket part. Expect plastic housing and basic copper contacts. It works fine for occasional use but may not last as long as OEM in heavy-duty or commercial mowing.
• Installation – Very easy: disconnect battery, remove two wires from the old solenoid, unbolt it, bolt in the new one, and reconnect. No special tools needed.
• Common gotcha – The small spade terminal can be fragile. Don’t overtighten the nut on the large studs, and ensure the spade connector is pushed on fully.
• Test before reassembly – With the battery reconnected, listen for a click when you turn the key. No click means a bad solenoid, a dead battery, or a faulty ignition switch.

Should You Buy It

If you need a cheap, quick fix for a no-start or intermittent starting issue on a residential lawn tractor, this solenoid is a solid value. It’s not built for commercial abuse, but for weekend mowing it does the job. Skip it if you want a heavy-duty sealed unit or need a four-post design.