Craftsman Intek Plus 18 Hp Engine Wont Crank

Craftsman Intek Plus 18 HP Engine Won’t Crank: Complete Troubleshooting Guide

Is your Craftsman riding mower with an Intek Plus 18 HP engine refusing to crank? Few things are more frustrating than preparing to mow your lawn only to discover your Craftsman Intek Plus 18 HP engine won’t crank at all.

This comprehensive guide will walk you through the most common causes and effective solutions to get your mower running again quickly.

Key Takeaways:

Check battery connections and voltage before anything else
Inspect the starter solenoid for clicking sounds or damage
Examine the compression release mechanism, a common failure point on Briggs and Stratton engines
Ensure proper spark plug condition and connection
Verify safety switches are functioning correctly
Regular maintenance prevents most cranking issues

Quick Answer: When a Craftsman Intek Plus 18 HP engine won’t crank, the most common causes are a dead battery, faulty solenoid, damaged starter motor, bad safety switches, or compression system issues. Begin troubleshooting with the battery and electrical components before moving to mechanical problems like the compression release system.

Understanding the Craftsman Intek Plus 18 HP Engine

The Craftsman Intek Plus 18 HP engine, manufactured by Briggs and Stratton, powers many popular riding mowers. These engines feature overhead valve (OHV) technology, providing better fuel efficiency and longer engine life. However, like all mechanical systems, they can develop issues over time that prevent proper cranking.

Briggs and Stratton’s Intek Plus series was designed to offer reliable performance for homeowners with larger properties. While generally dependable, certain components in these engines are prone to failure after extended use. Understanding how this engine works is the first step in diagnosing why your Craftsman Intek Plus 18 HP engine won’t crank.

The cranking system consists of several key components working together: the battery, starter motor, solenoid, ignition switch, and safety switches. Additionally, the engine’s compression system plays a critical role, particularly the compression release mechanism designed to make starting easier. When any of these components fails, the engine may refuse to crank.

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Battery and Electrical Issues Preventing Engine Cranking

The most common reason a Craftsman Intek Plus 18 HP engine won’t crank is related to the battery or electrical system. When you turn the key and nothing happens, start your troubleshooting here.

Battery Problems

A weak or dead battery is the number one cause of cranking issues. Here’s how to check:

Inspect battery terminals for corrosion or loose connections
Clean terminals with a wire brush and baking soda solution if corroded
Test battery voltage with a multimeter (should read 12.6V when fully charged)
Try jump-starting the mower with jumper cables
Check for parasitic drains that might be depleting the battery when not in use

Many Craftsman mower owners discover that simply replacing an old battery solves their cranking problems. Batteries typically last 3-5 years in riding mowers, so if yours is older, replacement may be the simplest solution.

Solenoid and Starter Motor Issues

If the battery checks out fine but your Craftsman Intek Plus 18 HP engine still won’t crank, the next components to examine are the solenoid and starter motor:

Listen for a clicking sound when turning the key - this indicates the solenoid is attempting to engage
Check solenoid connections for tightness and corrosion
Test the solenoid with a multimeter for proper function
Inspect the starter motor for damage or wear
Try bypassing the solenoid with a screwdriver (with extreme caution) to test the starter motor directly

The starter solenoid acts as a relay between the ignition switch and the starter motor. When it fails, it can’t deliver the electrical signal needed to activate the starter motor. Replacement solenoids are relatively inexpensive and simple to install.

Ignition Switch and Wiring Problems

Another potential electrical issue could be with the ignition switch itself or the wiring:

Check for blown fuses related to the ignition system
Inspect wiring harnesses for damage, particularly from rodents
Test the ignition switch with a multimeter for continuity
Look for loose connections throughout the electrical system
Ensure the key is functioning properly in the ignition switch

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Compression Release Mechanism Issues

A unique feature of Briggs and Stratton engines, including the Intek Plus 18 HP, is the automatic compression release (ACR) mechanism. This system makes the engine easier to start by reducing compression during cranking. When this system fails, the engine becomes extremely difficult or impossible to crank.

How the Compression Release Works

The compression release mechanism consists of:

A flywheel with weighted pawls
A camshaft with a compression release lobe
Springs that control the timing of the release

During normal operation, this system temporarily holds one valve slightly open during cranking to reduce compression, making it easier for the starter to turn the engine. Once the engine reaches operating speed, centrifugal force disengages the mechanism, allowing full compression for normal operation.

Signs of Compression Release Failure

You might have compression release problems if:

The engine is extremely hard to turn over manually
The starter motor strains excessively when attempting to crank
The engine cranks normally with the spark plug removed but not when installed
You hear grinding noises during cranking attempts

Many Briggs and Stratton Intek engines develop compression release problems after several years of use. Unfortunately, fixing this issue often requires partial disassembly of the engine to access the camshaft and flywheel.

Fixing Compression Release Problems

To address compression release issues:

Remove the engine shroud and inspect the flywheel
Check for broken or stuck compression release components
Consider using a compression release bypass technique as a temporary solution
For permanent repair, replacement of the camshaft assembly may be necessary

Safety Switch and Interlock System Problems

Modern riding mowers, including those with Craftsman Intek Plus 18 HP engines, have multiple safety switches that can prevent the engine from cranking if triggered. These systems are designed to protect the operator but can cause frustration when they malfunction.

Common Safety Switch Locations

Safety switches that may prevent cranking include:

Seat safety switch
Brake/clutch safety switch
PTO (Power Take-Off) safety switch
Transmission neutral safety switch

When any of these switches detect an unsafe condition (like the operator not being in the seat or the blades being engaged), they prevent the engine from cranking. However, these switches can fail or become misaligned over time.

Bypassing Safety Switches for Testing

To determine if a safety switch is causing your cranking issue:

Locate the switch in question (consult your owner’s manual)
Disconnect the wiring connector from the switch
Use a short wire to temporarily bridge the connector terminals
Attempt to start the engine

Important: Only bypass switches temporarily for testing purposes. Never operate the mower with safety systems permanently disabled.

If bypassing a switch allows the engine to crank, you’ve identified the faulty component. Replace the switch rather than leaving it bypassed, as these safety features are important for preventing accidents.

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Fuel System Issues Affecting Engine Start

While fuel system problems typically cause an engine to crank but not start, some fuel-related issues can actually prevent proper cranking as well.

Fuel Solenoid Problems

Many Intek Plus engines have an electric fuel solenoid that can affect cranking:

The fuel solenoid controls fuel flow to the carburetor
If seized or stuck, it can create excessive resistance
This resistance can make the engine harder to crank
Test by disconnecting the fuel solenoid and attempting to crank

Hydrolocked Engine

A condition called hydrolock can prevent cranking:

Occurs when fuel or oil floods the cylinder
The incompressible liquid prevents the piston from moving
Often happens after tipping the mower or overfilling with oil
Removing the spark plug and turning the engine by hand can clear the liquid

If your engine has been sitting unused for a long period or if the carburetor has been leaking, fuel may have seeped into the cylinder, causing hydrolock. This condition prevents the engine from cranking because liquids cannot be compressed like air.

Mechanical Issues Preventing Proper Cranking

Beyond electrical and fuel problems, several mechanical issues can prevent your Craftsman Intek Plus 18 HP engine from cranking properly.

Seized Engine Components

After long periods of disuse or lack of lubrication, engine components can seize:

Pistons can become stuck in cylinders
Crankshaft bearings can freeze
Valves can become stuck in open or closed positions

To check for a seized engine:

Remove the spark plug
Insert a wooden dowel into the cylinder
Try to rotate the engine by hand using the starter pulley
If you can’t turn it at all, internal components may be seized

Seized engines typically require significant disassembly and repair, sometimes making replacement the more economical option.

Damaged Flywheel Key

The flywheel key is a small metal piece that aligns the flywheel with the crankshaft:

If sheared or damaged, it can affect engine timing
This can make the engine extremely difficult to crank
Check by removing the flywheel and inspecting the key
Replace if any damage is visible

A sheared flywheel key often results from the blade striking a hard object or from attempting to start the engine with the blade engaged in tall grass.

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Preventative Maintenance to Avoid Cranking Issues

Regular maintenance is the best way to prevent your Craftsman Intek Plus 18 HP engine from developing cranking problems in the first place.

Regular Maintenance Schedule

Follow this maintenance schedule:

Change oil every 25-50 hours of operation
Replace air filter annually or when dirty
Replace fuel filter annually
Clean or replace spark plug every season
Check battery connections monthly
Keep cooling fins clean to prevent overheating
Store properly during off-season

Proper Storage Techniques

If storing your mower for the winter or extended periods:

Add fuel stabilizer to the tank
Run the engine for a few minutes to circulate the stabilized fuel
Remove the battery and store it in a cool, dry place
Charge the battery monthly during storage
Cover the mower to protect from dust and moisture
Consider changing the oil before storage

By following these maintenance steps, you’ll significantly reduce the chances of encountering cranking problems when you next need to use your mower.

Professional Repair vs. DIY Solutions

When facing engine cranking issues, you must decide whether to attempt repairs yourself or seek professional help.

When to Call a Professional

Consider professional help when:

You lack the necessary tools or mechanical knowledge
Internal engine components need replacement (camshaft, crankshaft, etc.)
Electrical troubleshooting goes beyond basic testing
The repair requires specialized equipment
The cost of parts approaches the value of the mower

DIY-Friendly Repairs

Many cranking issues can be resolved at home:

Battery replacement and connection cleaning
Solenoid replacement
Safety switch testing and replacement
Spark plug replacement
Basic fuel system maintenance

For homeowners with mechanical aptitude, online resources and service manuals can guide you through many repairs that would otherwise cost hundreds at a repair shop.

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FAQ: Common Questions About Craftsman Intek Plus 18 HP Engine Cranking Issues

Why won’t my Craftsman lawn mower turn over?

Your Craftsman lawn mower may not turn over due to a dead battery, faulty solenoid, broken starter motor, safety switch issues, or mechanical problems such as a seized engine or compression release failure. Start troubleshooting with the battery and electrical components as these are the most common causes.

What causes a Briggs and Stratton engine not to turn over?

Briggs and Stratton engines, including the Intek Plus series, often fail to turn over due to compression release mechanism failures, which make the engine too difficult to crank. Other common causes include electrical issues, seized internal components, or a sheared flywheel key affecting engine timing.

Why will my riding mower not crank?

A riding mower may not crank when safety switches detect an unsafe condition, the battery is dead, connections are corroded, or the solenoid/starter motor has failed. Check that you’re in neutral, the brake is engaged, the PTO is disengaged, and you’re properly seated to satisfy safety interlocks.

Why won’t my mower engine turn over?

If your mower engine won’t turn over, check for a hydrolock condition (liquid in the cylinder), seized internal components, or excessive resistance from the compression release mechanism. Remove the spark plug and try turning the engine by hand to diagnose mechanical binding issues.

How do I know if my lawn mower solenoid is bad?

A bad lawn mower solenoid often produces a clicking sound when you turn the key but doesn’t engage the starter. To test it, listen for the click when turning the key, check for 12V at the small terminal when the key is turned, and ensure continuity between the large terminals when the solenoid is energized.

Can a spark plug cause a lawn mower not to crank?

While a bad spark plug typically causes starting rather than cranking issues, an improperly gapped or damaged spark plug can increase compression resistance, making the engine harder to crank. Remove the spark plug and try cranking – if it turns over easily without the plug, compression issues may be the cause.

How do I bypass the compression release on a Briggs and Stratton engine?

As a temporary measure, you can bypass a failed compression release by removing the spark plug, placing a few drops of oil in the cylinder, and reinstalling the plug finger-tight (not fully tightened). This reduces compression and allows for easier cranking. This is not a permanent solution but can help diagnose the issue.

Final Words: Getting Your Craftsman Intek Plus 18 HP Engine Cranking Again

Dealing with a Craftsman Intek Plus 18 HP engine that won’t crank can be frustrating, but systematic troubleshooting often leads to a solution. Start with the simplest possibilities – the battery and electrical connections – before moving to more complex issues like the compression release mechanism.

Regular maintenance remains your best defense against cranking problems. By properly caring for your Craftsman mower’s engine, you’ll extend its life and reduce the likelihood of encountering starting issues in the future.

Whether you choose to tackle repairs yourself or seek professional help, understanding the potential causes puts you in a better position to get your mower running again quickly and efficiently.