After a long winter, it’s frustrating to find your Cub Cadet lawn mower won’t start when spring finally arrives. This is a common problem for both riding and walk-behind models, whether gas or battery powered. The good news? Most post-winter starting issues can be solved at home with a few simple checks and maintenance steps. This guide covers every reason your Cub Cadet mower might not start after winter—and exactly how to get it running smoothly for the mowing season ahead.
Quick-Check: Why Won’t My Cub Cadet Start After Winter?
- Old, stale, or contaminated gasoline left in the tank
- Dead or uncharged battery (for riding and battery models)
- Clogged carburetor or fuel lines (gummed up from old fuel)
- Spark plug fouled, corroded, or disconnected
- Rodent or insect nests blocking air filter, exhaust, or wiring
- Choke not set, or primer bulb not working (gas models)
- Safety switch (seat, brake, PTO, bail lever) not fully engaged
- Oil level too low (many engines have a safety shutoff)
- Clogged or dirty air filter and/or fuel filter
- Blade or engine jammed by debris under the deck
- Blown fuse, faulty ignition switch, or damaged wiring
1. Replace Old Gasoline and Clean the Fuel System
- Drain the fuel tank—gasoline goes stale in as little as 30 days. Use a siphon or remove the tank to empty old fuel completely.
- Clean the carburetor: Spray carb cleaner into the carb throat, and if the engine tries to run, remove and clean the carburetor jets and float bowl. Gummed-up carbs are the #1 springtime no-start cause.
- Replace or clean the fuel filter if dirty or clogged.
- Add fresh, clean, ethanol-free gasoline with fuel stabilizer if possible.
2. Battery and Electrical System Checks (Riding and Battery Models)
- Charge the battery fully—most batteries lose charge during winter. If the battery is over 3 years old or won’t hold a charge, replace it.
- Clean any corrosion from battery terminals with a wire brush. Tighten cable connections.
- Inspect for blown fuses (near the battery or under the seat/panel). Replace as needed.
- Check for chewed or disconnected wires, especially if mice or rodents could get into your storage area.
- Try jump-starting the mower with a 12V car battery if you suspect a dead battery (for riding mowers only).
3. Spark Plug and Ignition System
- Remove the spark plug and inspect for black soot, corrosion, or oil. Clean with a wire brush or replace with a new plug (set gap to 0.028–0.030 inches unless otherwise specified).
- Reconnect the spark plug wire securely.
- Test for spark: Ground the plug to the engine and crank—look for a blue spark. No spark means the coil or switch may need replacement.
4. Air Filter, Fuel Filter, and Engine Breathing
- Remove and clean or replace the air filter—dust, leaves, and mouse nests are common after storage.
- Check the intake and exhaust for any blockages or nesting materials.
- Replace the fuel filter annually or whenever it looks dirty.
5. Choke, Primer, and First Start Techniques
- Set the choke to “ON” for the first start after winter, and press the primer bulb 2–3 times if your mower has one.
- If the primer bulb is cracked or does not squirt fuel, replace it.
- After a few failed start attempts, let the mower sit for 10–15 minutes to avoid flooding, then try again with proper choke and priming.
6. Safety Switches and Controls
- Riding mowers: Sit in the seat, set parking brake, and ensure the blade (PTO) is disengaged. Most models require these steps or the starter will not engage.
- Push/walk-behind mowers: Squeeze the bail (safety) bar tightly against the handle while starting.
- Wiggle all levers and controls if a switch is stuck after storage—moisture and rust can make contacts sticky.
7. Blades, Deck, and Obstructions
- Disconnect spark plug wire or battery before checking under the mower deck.
- Look for sticks, heavy grass, or nests that could jam the blade or engine flywheel. Remove all debris before trying to start.
- Spin the blade by hand (wear gloves). It should move freely; resistance could mean an engine or starter jam.
8. Additional Electrical Checks (If No Click, No Crank)
- Check ignition switch and starter solenoid—turn the key and listen for a click. No sound? Test/replace switch or solenoid as needed.
- Inspect main ground wire and all connections—loose or corroded grounds prevent starting.
- Check for rodent-damaged or disconnected wires (look under seat, panels, and near the engine).
Preventive Maintenance for Easy Spring Starts
- Drain fuel at end of each season, or use fuel stabilizer before winter
- Store the battery indoors and charge every 6–8 weeks during winter
- Clean and replace air, fuel, and oil filters every spring
- Lubricate cables, linkages, and controls before first use
- Inspect for rodent nests, damaged wiring, and blockages in spring
- Check oil level and top off before first start—most engines have a safety shutoff for low oil
Frequently Asked Questions (FAQ)
Why won’t my Cub Cadet start after sitting all winter?
The most common reasons are old/stale fuel, a dead battery, a fouled spark plug, clogged carburetor, or blocked air/fuel filters. Always start by draining fuel, charging the battery, and inspecting these items.
How do I know if the carburetor is the problem?
If your mower only starts briefly with starting fluid, or not at all, and you’ve checked fuel, spark, and air, the carburetor is likely clogged with old fuel varnish. Remove and clean or rebuild it for best results.
Can rodents really cause mower no-starts?
Absolutely. Mice often nest in mower engines over winter and chew wires or block airways. Inspect for chewed wires or nesting material if your mower is dead after storage.
What if my riding mower has power, but won’t crank?
Ensure the seat and brake switches are engaged, blade/PTO is off, and check the solenoid, ignition switch, and fuses. Battery connections must be clean and tight.
Should I do a full tune-up every spring?
Yes, for easy starts and long engine life. Change oil, replace spark plug and filters, lubricate moving parts, and clean out old grass/debris from deck and engine area.
Conclusion: Get Your Cub Cadet Mower Ready for Spring
Most Cub Cadet no-start problems after winter are caused by old fuel, dead batteries, clogged carburetors, or safety switches out of position. With a simple spring tune-up and this troubleshooting guide, you’ll be back to mowing fast—and your mower will thank you with strong, reliable starts all season!
Ready for a perfect first mow? Follow these steps and keep your Cub Cadet running strong year after year!