Craftsman Lawn Mower Does Not Start: Fix It Today

Pulled the cord and nothing? Don’t worry—this happens a lot with Craftsman lawn mowers. I’ve had the same problem more than once. Most of the time, it’s something simple. Maybe the gas is old. Maybe the spark plug is dirty. Or the carburetor is clogged.

After years of mowing and fixing engines, I’ve learned a few easy tricks. You don’t need to take it to a shop. Let me show you what works. You’ll be back to cutting grass in no time—and without all the stress.

Know the Problem: Two Kinds of No-Start

When your Craftsman mower won’t start, first ask: What kind of “no-start” is it? There’s a big difference between a mower that tries to start and one that does nothing at all.

Crank-No-Start vs. No-Crank

• Crank-no-start: The engine turns over but doesn’t run.
• No-crank: Nothing. No sound. No movement. Just silence.

Quick Tip: How to Tell

• Hear the engine spin or sputter? That’s crank-no-start.
• Hear nothing? That’s no-crank.

One time, I pulled the cord over and over—nothing. Turns out the blade was stuck on a branch. Knowing the type saved me hours of work.

Common Causes (Grouped by Type)

Crank-No-Start:

• Bad spark plug
• No spark
• Dirty carb or clogged fuel line
• Old gas
• Flooded engine
• Dirty air filter

No-Crank:

• Jammed blade
• Safety bar not held down
• Broken pull cord
• Bad starter or switch (on electric models)
• Seized engine (rare)

Easy Checks First

Before grabbing tools, check the basics. These quick steps may solve the problem fast.

Is the Safety Bar Down?

Most Craftsman walk mowers have a safety bar. You must hold it tight while starting.

I’ve tried to start mine with the bar half-squeezed. Nothing. Held it tighter—started first pull.

Is the Gas Fresh?

Old gas is a top cause of no-starts. Gas goes bad in 30–60 days. It can leave gummy stuff in the carb.

Fuel Tips:

• Use gas within 30 days
• Add fuel stabilizer for storage
• If it smells bad or looks cloudy—drain it

I once left gas in my mower all winter. In spring, it wouldn’t run. I drained it, added fresh fuel—and it started right up.

Did You Prime It?

Most Craftsman mowers have a primer bulb. Push it 2–3 times before starting. It sends fuel into the carb.

I’ve skipped this step before and thought the mower was broken. Hit the primer, pulled the cord—it started right away.

Step-by-Step Troubleshooting Guide

If your Craftsman mower still won’t start after the quick checks, don’t worry. Here’s how I go through it—step by step—until I find the fix. I check fuel, spark, air, and timing.

Check the Spark Plug

This is the first thing I look at. It’s easy to get to and gives lots of clues.

How I Check Mine:

I pull off the plug boot. Then I use a socket wrench to remove the spark plug. I clean off dirt first, so it doesn’t fall in. Be gentle—the threads are soft.

What Bad Looks Like:

• Dry black tip: Carbon buildup (bad fuel mix or too much oil)
• Wet tip: Engine might be flooded
• White or melted tip: Overheating or wrong plug

When to Replace:

Use a gap tool to check the space. Most Craftsman mowers need 0.030 inches—but check your manual. I replace mine every spring.

Make Sure There’s Spark

Even if the plug looks okay, you still might not have spark.

How I Test It:

• Basic way: Connect the plug wire. Hold the plug against the engine. Pull the cord. Look for a blue spark.
• Better way: Use a spark tester. I got one for under $10.

Check the Fuel System

Old fuel and dirty carbs cause lots of problems.

Signs of Fuel Trouble:

• Starts, then dies
• Only runs with starter spray
• Runs rough or surges

How I Clean the Carb (Fast DIY):

1. Turn off the fuel valve or clamp the line
2. Remove the air filter and the carb bowl
3. Spray carb cleaner in all jets and holes
4. Let dry and put it back together

When to Use Spray vs. Full Cleaning:

• Use spray if it was running recently
• Do a full clean (soak the carb) if it sat for months with gas in it

Check the Air Filter

Your mower needs clean air. A clogged filter chokes the engine.

How to Clean It:

• Foam filter: Wash with soapy water. Dry it. Add a bit of oil.
• Paper filter: Tap off the dust. If it’s dark or torn—replace it.

I always keep a spare filter on hand—especially during pollen season.

Check the Flywheel Key

If your mower backfires or won’t start after hitting something, this might be why.

How I Broke Mine:

I hit a root hard. The blade stopped. After that, the mower cranked but didn’t start. I had spark and fuel—but no fire. The flywheel key was broken.

What a Backfire Means:

Backfiring often means bad engine timing. That’s usually from a sheared flywheel key. The spark and piston are out of sync.

How to Fix It:

1. Remove the top cover and flywheel nut
2. Use a puller (or two screwdrivers) to lift the flywheel
3. Replace the soft metal key
4. Re-tighten everything

Electrical & Coil Troubleshooting

Still no spark after changing the plug? You might have a deeper issue. Here’s how I found the fix on one of my older Craftsman mowers.

Kill Wire Test

Sometimes the safety switch blocks spark without warning.

What I Did:

I unplugged the kill wire from the coil. Pulled the cord—and boom, the mower started!

Why It Works:

The kill wire shuts off the engine by grounding the coil. If the wire is damaged or the switch is stuck, no spark will reach the plug.

Safety Tip:

With the wire off, the engine won’t stop unless you choke it or pull the plug wire. Be careful and stay alert.

Test the Ignition Coil

If the kill wire is fine, check the coil itself. A multimeter makes this easy.

Steps:

1. Set the multimeter to ohms (Ω)
2. Disconnect the coil
3. Test both sides:

• Small leads (primary): Should read 0.6–1.2 ohms
• Plug wire to metal tab (secondary): Should read 2,500–5,000 ohms

What Happened to Me:

One coil showed no reading at all. That meant it was dead. I swapped it out, and the mower fired up on the first pull.

Set the Coil Gap

Even a good coil won’t work if the gap to the flywheel is wrong.

How I Do It:

I slide a business card between the coil and the flywheel magnet. Then I tighten the bolts. Done.

Why It Works:

That gives you a gap of about 0.010–0.015 inches. Perfect for most Craftsman mowers.

Compression Check (Last Resort)

Still no start? If you’ve got spark, fuel, and air—but it still won’t run—it might be low compression.

What I Faced:

One mower spun fast, had spark, smelled like fuel—but wouldn’t even try to run. After hours of guesswork, I checked compression.

Tool I Used:

A $25 tester from Amazon. It screws into the spark plug hole.

How I Used It:

1. Took out the spark plug
2. Screwed in the tester
3. Pulled the cord 4–5 times
4. Read the gauge

What I Saw:

Only 40 PSI. That’s too low. A healthy engine should show 60–100+ PSI.

What It Meant:

• Worn piston rings
• Scratched cylinder
• Maybe a blown head gasket or stuck valve

Easy Fixes for Walk-Behind Craftsman Mowers

Some problems are more common with walk-behind models. They might not be engine issues, but they can stop your mower just the same. I’ve had both happen to me—more than once.

Pull Cord Stuck?

If your cord won’t move, don’t panic. It might seem like the engine is locked up. But often, it’s something simple.

Two common causes:

• The brake is still on
• Something’s blocking the blade

What I Do First:

I tip the mower back just a bit—always with the spark plug wire off—and look under the deck.

What I’ve Found:

• A rock jammed between the blade and the deck
• Wet grass wrapped around the shaft

How to Check It Safely:

1. Unplug the spark plug wire
2. Tilt the mower back (carb side up) to avoid flooding
3. Look under the deck for sticks, grass, or rocks
4. Spin the blade by hand (use gloves!) to see if it’s free

Handle Safety Switch Problems

Most Craftsman push mowers have a safety bar on the handle. It’s called a bail lever. You must hold it down to start or run the engine.

If the cable breaks or comes loose, the mower won’t start. You might pull the cord—and nothing happens.

What Happened to Me:

One summer, my mower just stopped starting. I checked fuel, spark, air—everything. But the cable on the bail lever had come loose. I tightened it. First pull—started right up.

What to Look For:

• Handle feels loose? Cable or spring might be broken
• Cord feels normal, but engine does nothing? Bail bar might not be working
• Electric mower won’t crank? Switch might be disconnected

How to Fix It:

1. Check the cable near the flywheel brake
2. Squeeze the handle—see if the spring and cable move
3. If the cable is frayed or snapped, replace it

When to Call a Pro

Sometimes, no matter what you do, your mower still won’t start. I’ve been there too. One of mine had spark, fuel, and good compression—but wouldn’t run. That’s when I knew it was time to get help.

DIY Doesn’t Always Work

If you’ve already tried:

• Fresh gas
• New spark plug
• Cleaned carb
• Working coil
• Good compression

…and it still won’t start, then the issue might be serious:

• Worn piston rings
• A blown head gasket
• Bent valve or other engine damage

These fixes take special tools and time. You may need to take the engine apart. Unless you enjoy small engine repair, it’s not worth the trouble.

When It’s Not Worth Fixing

Here’s how I decide:

• Is the mower more than 8–10 years old?
• Is the repair cost close to the price of a new one?
• Do I spend more time fixing than mowing?

If I say “yes” to two or more, I start shopping for a new one. For most U.S. yards, it’s cheaper and easier to replace than repair—especially if parts and labor cost over $200.

Where to Get Help

Craftsman mowers are easy to service. You can find help at:

• Sears Home Services – Still supports Craftsman models
• Lowe’s and Ace Hardware – Some stores fix small engines
• Authorized Repair Shops – Check your mower’s manual
• Local small engine shops – Ask around; some are better than big chains

Simple Maintenance = Fewer Problems

Over time, I’ve learned that a few habits keep my mower running strong. Here’s my seasonal checklist.

My Spring and Fall Routine

• Drain old gas – I run the mower dry at the end of the season
• Use fuel stabilizer – Helps gas last longer
• Replace the spark plug – Once a year is plenty
• Clean the air filter – More often in dusty weather
• Check the oil – Add or change it before the first mow

Read More: Milwaukee Lawn Mower Review

Final Takeaway

Let’s keep it simple:

• Old gas? Drain it and refill
• No spark? Check plug, coil, and kill switch
• Air problem? Clean or swap the filter
• Hit something? Check the flywheel key
• Still stuck? Do a compression test—and decide

I’ve made all the mistakes so you don’t have to. This stuff may seem tricky, but trust me—if I can figure it out, so can you.

Still stuck? Drop your mower model and what it’s doing in the comments—I’ll help if I can.

FAQs – Craftsman Lawn Mower Does Not Start