Bolens Bl160 Spark Plug

As I stand in my shed looking at my trusty Bolens BL160 string trimmer, I can’t help but feel a sense of pride. This reliable workhorse has helped me maintain my lawn’s edges for years now. But like any relationship, it requires care and attention—especially when it comes to that tiny but mighty component: the spark plug. After years of trial and error (and yes, some frustrating moments), I’ve compiled everything I’ve learned about keeping this crucial part in top condition. Whether you’re a first-time owner or a seasoned pro looking to troubleshoot, this comprehensive guide will walk you through everything you need to know about your Bolens BL160’s spark plug.

Understanding the Heart of Your Trimmer

The first time my Bolens BL160 refused to start on a Saturday morning when I had a yard full of guests coming over that afternoon, I panicked. After frantically searching online and consulting with a neighbor who knows his way around lawn equipment, I discovered that the spark plug is essentially the heartbeat of your string trimmer’s engine. This tiny component creates the electrical spark that ignites the fuel-air mixture in your engine’s combustion chamber, bringing your trimmer to life.

When I first purchased my Bolens BL160, I didn’t give much thought to spark plug maintenance. Like many homeowners, I assumed that as long as I kept the gas tank filled and the string properly loaded, everything would run smoothly. It wasn’t until I experienced that first non-start situation that I realized how crucial this small part really is.

The spark plug in your Bolens BL160 is constantly working whenever your trimmer is running. With each cycle of the engine, it creates a precisely timed spark under extreme conditions. It’s exposed to high temperatures, pressure, and combustion byproducts. Over time, this harsh environment takes its toll, causing carbon deposits to build up, electrodes to wear down, and performance to degrade.

Understanding this helped me realize why my trimmer sometimes struggled to start, lacked power, or ran roughly. The spark plug wasn’t just another part—it was a critical component that needed regular attention.

The Correct Spark Plug for the Bolens BL160

One of the most common questions I had when I first needed to replace my spark plug was simply: which one is the right one? After some research and a few missteps, I discovered that the Bolens BL160 typically uses a Champion RCJ6Y spark plug or its equivalent.

However, there are compatible alternatives from other manufacturers that work just as well:

• NGK BPMR7A
• Torch L7RTC
• Bosch WSR6F

The important thing I learned is that using the correct spark plug specification is crucial for proper engine performance. When I once tried using a “similar” plug that wasn’t quite right, my trimmer ran poorly and eventually stopped working altogether. I had to remove it and install the correct one, which immediately solved the problem.

The specifications matter because they ensure the plug will fit properly in your engine and create the right spark at the right time. The heat range, thread size, and electrode configuration are all specifically designed for your trimmer’s engine.

When purchasing a replacement, I always bring the old spark plug with me to the store or have the exact model number ready when ordering online. This simple step has saved me from buying the wrong part multiple times.

Understanding Spark Plug Gap for the Bolens BL160

One aspect of spark plugs that confused me initially was the concept of “gap.” I didn’t realize that the small space between the center and ground electrodes on the spark plug was adjustable and critically important to performance.

For the Bolens BL160, the recommended spark plug gap is typically 0.025 inches (0.635 mm). This precise measurement ensures that the spark has the right intensity to ignite the fuel mixture effectively.

The first time I replaced my spark plug, I didn’t check the gap, assuming it was preset from the factory. While many new plugs come pre-gapped, I’ve found that it’s always worth verifying with a gap tool before installation. Sometimes they get bumped during shipping or simply aren’t set to the exact specification your trimmer needs.

I learned the hard way that an incorrect gap can cause:

• Hard starting
• Rough idling
• Poor acceleration
• Reduced power
• Increased fuel consumption

After experiencing these issues, I invested in an inexpensive spark plug gap tool (which cost less than $5) and now check every new plug before installation. The difference in performance is noticeable when the gap is set correctly.

To adjust the gap, I gently bend the ground electrode using the gap tool until the specified measurement is achieved. This delicate operation requires patience—I once bent an electrode too far and had to start over with a new plug!

How to Replace the Spark Plug on Your Bolens BL160

The first time I tried replacing my spark plug, I was intimidated. Working on engines seemed like something best left to professionals. But after watching a few videos and reading some guides, I realized it was actually quite straightforward. Now, it’s a maintenance task I perform with confidence.

Here’s my step-by-step process for replacing the spark plug in a Bolens BL160 trimmer:

1. Safety first: Make sure the engine is completely cool before beginning. I once burned my finger trying to remove a plug from a recently-run trimmer—not a mistake I’ll repeat!
2. Disconnect the spark plug boot: Firmly grasp the rubber boot that connects to the top of the spark plug and pull it straight off. Don’t pull on the wire itself, as this can damage the connection.
3. Clean the area: I use compressed air or a small brush to remove any debris around the spark plug base. This prevents dirt from falling into the cylinder when the plug is removed.
4. Remove the old plug: Using a spark plug socket (typically 3/4″ or 19mm for the Bolens BL160), turn the plug counterclockwise until it’s loose enough to remove by hand. I keep the socket on the plug to prevent dropping it as it comes free.
5. Inspect the old plug: This is something I didn’t do initially but now find invaluable. The condition of the old plug tells you a lot about how your engine is running:
   • Tan/light brown deposits: Normal operation
   • Black, sooty deposits: Rich fuel mixture or oil in the fuel
   • White/blistered appearance: Engine running too hot
   • Wet with fuel: Flooding issues
6. Gap the new plug: Using a gap tool, check and adjust the new plug to the recommended 0.025 inches.
7. Install the new plug: Thread it in by hand initially to avoid cross-threading, then tighten with the socket. I’m careful not to overtighten—just snug is sufficient (about 1/4 turn after the plug seats).
8. Reconnect the boot: Press the boot firmly onto the top of the plug until it clicks or seats completely.

The first time I completed this process, my trimmer started on the second pull, and I felt an immense sense of satisfaction at having successfully maintained my own equipment.

Tools Needed for Spark Plug Replacement

Before my first spark plug replacement, I made the mistake of starting without having all the necessary tools on hand. This led to a frustrating experience and a trip to the hardware store in the middle of the job. Now, I make sure I have everything ready before I begin.

The essential tools for changing a spark plug on a Bolens BL160 include:

1. Spark plug socket (3/4″ or 19mm): This specialized socket has a rubber insert that holds the plug securely and prevents damage to the ceramic insulator.
2. Ratchet or socket wrench: To turn the socket. A 3/8″ drive works well for most trimmers.
3. Extension bar (optional): Sometimes helpful for reaching the spark plug in tight spaces.
4. Spark plug gap tool: A simple gauge for measuring and adjusting the electrode gap.
5. Wire brush (optional): Useful for cleaning the threads in the cylinder head if they’re dirty or corroded.
6. Anti-seize compound (optional): I apply a tiny amount to the threads of the new plug to make future removal easier, especially since these trimmers often work in humid conditions.
7. Clean rag: For wiping away debris and cleaning your hands.

I keep all these tools together in a small pouch in my shed, so they’re ready whenever I need to perform this maintenance task. The entire investment was less than $20, and they’ve paid for themselves many times over in convenience and saved repair costs.

Checking if Your Spark Plug is Working

There have been times when my trimmer wouldn’t start, and I wasn’t sure if the spark plug was the culprit. Through trial and error, I’ve learned a few methods to test whether a spark plug is functioning properly.

The simplest test I use requires:

1. Removing the spark plug while leaving it connected to the spark plug boot
2. Placing the metal thread portion against the engine block (to ground it)
3. Pulling the starter cord while watching for a spark between the electrodes

The first time I tried this, I didn’t see anything until I realized I needed to do it in a shaded area. In bright sunlight, the spark can be difficult to see. When I moved to a darker corner of my garage, the healthy blue spark was clearly visible.

Another issue I’ve encountered is that this test requires pulling the starter cord, which can be difficult to do while simultaneously watching for the spark. I’ve found it helpful to have a family member pull the cord while I observe, or to use a spark plug tester tool, which has a clear window that makes the spark more visible.

If you don’t see a spark, it could indicate:

• A faulty spark plug
• Problems with the ignition coil
• Issues with the stop switch
• Damaged wiring

When my trimmer failed this test, replacing the spark plug solved the problem about 80% of the time. For the other cases, I needed to dig deeper into the ignition system.

Signs of a Bad Spark Plug

Over the years, I’ve become somewhat of a spark plug detective, learning to recognize the warning signs that indicate replacement is needed. Catching these symptoms early has saved me from being stranded with a non-functioning trimmer in the middle of a yard job.

The most common indicators of a failing spark plug I’ve experienced include:

1. Difficult starting: When my trusty Bolens that normally starts in 2-3 pulls suddenly needs 8-10 attempts, the spark plug is often the culprit.
2. Rough idling: A healthy trimmer should maintain a steady idle. When mine begins to sputter, surge, or die at idle, I check the spark plug first.
3. Loss of power: I once noticed my trimmer struggling with thick grass that it previously cut without effort. A worn spark plug was reducing the engine’s power output.
4. Increased fuel consumption: When I found myself refilling the tank more frequently than usual, a fouled spark plug was reducing combustion efficiency.
5. Visible damage: During routine inspection, if I notice a cracked ceramic insulator, excessive gap erosion, or heavy carbon deposits, it’s definitely time for replacement.

One particular instance stands out in my memory. I was trimming along my fence line when the engine suddenly cut out. After several failed restart attempts, I checked the spark plug and found it completely coated in black carbon deposits. The electrode was barely visible! A quick replacement had me back to work in minutes.

How Often to Replace Your Spark Plug

When I first purchased my Bolens BL160, I had no idea how frequently the spark plug should be replaced. I initially adopted the “if it ain’t broke, don’t fix it” approach, which led to unexpected breakdowns and frustration.

After consulting the manual and speaking with more experienced users, I learned that for typical homeowner use, replacing the spark plug annually or every 25-30 hours of operation is generally recommended. However, this can vary based on:

• How frequently you use your trimmer
• The conditions in which you operate it
• The quality of fuel you use
• Whether you use the correct oil mixture

I now keep a small notebook in my shed where I record maintenance dates and approximate hours of use. This simple system helps me stay ahead of potential problems by replacing parts before they fail.

For my personal use pattern—trimming my half-acre property every 1-2 weeks during the growing season—an annual replacement in early spring works perfectly. This ensures my trimmer is ready for the busy season ahead.

I’ve also found that if I use fuel that’s been sitting for more than a month, or if I accidentally mix the fuel incorrectly, the spark plug tends to foul more quickly. In these cases, I might replace it mid-season as well.

Can You Clean a Spark Plug Instead of Replacing It?

During my early days of trimmer ownership, I wondered if cleaning a spark plug could extend its life and save me a few dollars. After experimenting with this approach, I’ve found that cleaning can sometimes be effective for lightly fouled plugs, but it’s rarely a long-term solution.

My cleaning method involves:

1. Removing the plug carefully
2. Using a wire brush to remove carbon deposits from the electrodes and threads
3. Spraying with electronic parts cleaner to remove remaining residue
4. Allowing it to dry completely
5. Adjusting the gap if needed before reinstallation

I tried this on a plug that was causing my trimmer to run roughly, and it worked—for about an hour of operation. Then the problems returned, worse than before. When I finally replaced the plug with a new one, the difference was dramatic.

The reality I’ve come to accept is that while cleaning may provide a temporary fix in an emergency, the electrodes naturally wear down over time, and this erosion cannot be reversed. At around $3-5 per plug, replacement is an inexpensive maintenance item that provides significant performance benefits.

That said, I do keep a cleaned spare plug in my trimmer’s carrying case for emergencies. It’s saved me a few times when I’ve been working far from home and encountered problems.

Troubleshooting When Your Trimmer Won’t Start After Plug Replacement

One particularly frustrating experience I had was when my Bolens BL160 refused to start even after I’d installed a brand-new spark plug. I was convinced I’d done everything right, yet the trimmer stubbornly remained silent.

After some trial and error, I discovered several potential issues that can cause this problem:

1. Incorrect gap: I double-checked and found I had set the gap too wide. Adjusting it to the proper 0.025 inches solved the problem.
2. Loose connection: In my haste, I hadn’t pressed the spark plug boot firmly onto the plug. Ensuring it was fully seated restored the connection.
3. Cross-threading: Once, I accidentally cross-threaded a new plug, preventing proper contact. I had to carefully remove it and start over with a new plug, being extra careful with the initial threading.
4. Flooded engine: After multiple failed start attempts, the cylinder can become flooded with fuel. I learned to remove the plug, turn the trimmer upside down to drain excess fuel, wait 10-15 minutes, then try again.
5. Other engine issues: Sometimes, a non-starting condition isn’t related to the spark plug at all. Checking the air filter, fuel lines, and carburetor might be necessary.

The most valuable lesson I learned was to verify that the new plug is actually producing a spark (using the test method described earlier) before spending too much time on other troubleshooting steps.

The Consequences of Using the Wrong Spark Plug

Early in my trimmer ownership, I made what seemed like a minor mistake that led to major problems. The hardware store was out of the recommended spark plug, so I purchased one that looked “close enough.” This decision taught me an expensive lesson about the importance of using the correct specifications.

Using the wrong spark plug can lead to:

1. Engine damage: A plug with the wrong heat range can cause pre-ignition or overheating, potentially damaging the piston and cylinder.
2. Poor performance: I experienced significant power loss and rough running when using an incorrect plug.
3. Difficult starting: The wrong plug may create a weak spark or require more voltage than your ignition system can provide.
4. Reduced fuel efficiency: I noticed my trimmer consuming noticeably more fuel with the incorrect plug installed.
5. Physical damage: A plug with the wrong thread size or reach can physically damage the cylinder head—an expensive repair!

After running my trimmer for just 20 minutes with the incorrect plug, it began making alarming noises and eventually shut down completely. The diagnosis from my local small engine repair shop? The wrong spark plug had caused damage to the cylinder head threads and contributed to overheating.

The repair cost me over $80—far more than the couple of dollars I “saved” by using the wrong plug. Now I always ensure I’m using exactly the right specifications, even if it means waiting for the correct part to arrive.

Where to Buy Replacement Spark Plugs

Finding quality replacement spark plugs for the Bolens BL160 has become easier over the years as I’ve explored different purchasing options. Each source has its advantages and disadvantages.

Local Options:

1. Hardware stores: My local Ace Hardware and True Value both carry compatible spark plugs. The advantage is immediate availability and the ability to bring my old plug for comparison. The downside can be higher prices and occasionally limited selection.
2. Home improvement centers: Larger stores like Home Depot, Lowe’s, and Menards typically stock common spark plugs. I’ve found their prices to be reasonable, though their staff might not be as knowledgeable about specific requirements as a dedicated small engine shop.
3. Auto parts stores: Places like AutoZone, O’Reilly, and Advance Auto Parts carry extensive spark plug inventories. They often have computer systems that can cross-reference part numbers to find compatible options.
4. Small engine repair shops: These specialists usually stock quality plugs and provide expert advice. I’ve found their guidance invaluable, though their prices may be slightly higher.

Online Options:

1. Amazon and eBay: Offer convenience and often the best prices, especially when purchasing in bulk. I’ve bought multipacks that provide enough plugs for several years at significant savings.
2. Specialty outdoor equipment websites: Sites dedicated to lawn equipment often have exactly the right parts and helpful guides, though sometimes at premium prices.
3. Manufacturer websites: Going directly to Champion, NGK, or other spark plug manufacturers ensures you get authentic parts, though not always at the best price.

I typically keep two spare plugs on hand—one in my trimmer’s carrying case for emergencies and one in my maintenance supplies. This preparation has saved me from interrupted yard work on multiple occasions.

The Environmental Impact: Properly Disposing of Old Spark Plugs

Something I hadn’t considered when I first started maintaining my own equipment was what to do with the old spark plugs. After accumulating a few in a jar in my shed, I researched proper disposal methods.

Spark plugs contain metals that can be recycled, including copper, nickel, and sometimes precious metals in the electrodes. The ceramic insulators are also recyclable. However, they shouldn’t simply be thrown in your regular recycling bin.

I’ve found several responsible disposal options:

1. Auto parts stores: Many larger chains like AutoZone offer recycling programs for automotive parts, including spark plugs. I collect mine throughout the year and drop them off during a regular shopping trip.
2. Metal recyclers: Local scrap yards will often accept spark plugs as part of their metal recycling programs. Some even pay a small amount for them, though the quantity from trimmer maintenance is usually too small to be significant.
3. Hazardous waste collection: Some municipalities include spark plugs in their hazardous waste collection events. I check my local government website for dates and acceptable items.
4. Small engine repair shops: Many shops will take your old plugs for proper recycling when you purchase new ones from them.

Before disposal, I clean the old plugs of any oil or gasoline residue and place them in a small container to prevent loss of the small parts. This simple practice helps reduce the environmental impact of my yard maintenance activities.

Aftermarket vs. OEM Spark Plugs: Making the Right Choice

When I first started maintaining my Bolens BL160, I wondered whether I needed to stick strictly with original equipment manufacturer (OEM) spark plugs or if aftermarket options were acceptable. After trying various brands, I’ve formed some opinions based on personal experience.

OEM advantages:

• Guaranteed to meet exact specifications
• Often provide the most consistent performance
• May come with better warranty coverage

Aftermarket advantages:

• Usually less expensive
• More widely available
• Some premium brands may offer performance improvements

In my experience, high-quality aftermarket plugs from reputable manufacturers like Champion, NGK, Bosch, or Denso perform just as well as OEM plugs in the Bolens BL160. The key is ensuring they meet the exact specifications required for your trimmer.

I once purchased an ultra-cheap generic spark plug from an unknown manufacturer online. While it worked initially, it failed after just a few hours of operation. This experience taught me that while aftermarket can be fine, quality still matters.

For my own maintenance, I typically use NGK or Champion plugs purchased from a local auto parts store. They’ve provided reliable performance at a reasonable price, and I haven’t noticed any difference in starting or running compared to the original plug that came with my trimmer.

Can a Bad Spark Plug Cause Power Loss?

One question I initially had was whether a spark plug that still worked but was aging could affect the power output of my trimmer. Through experience, I’ve learned that the answer is a definitive yes.

Several years ago, I was trimming some thick brush along my property line when I noticed my Bolens BL160 struggling with growth it had previously handled with ease. The engine was running, but it lacked its usual power and would bog down under load. Thinking it might be a fuel issue, I checked the mixture and filter, but everything looked fine.

As a last resort, I replaced the spark plug, even though the trimmer was starting and running. The difference was immediate and dramatic. With the new plug installed, my trimmer cut through the thick vegetation like it was butter.

This experience taught me that a worn or fouled spark plug can still create enough spark to run the engine, but not enough to generate full power. The degraded spark may not ignite the fuel mixture completely or at the optimal moment in the combustion cycle, resulting in:

• Reduced power output
• Hesitation during acceleration
• Poor throttle response
• Increased fuel consumption
• Higher emissions

Now, if I notice any power loss in my trimmer, checking the spark plug is one of my first troubleshooting steps. In many cases, this simple and inexpensive replacement restores full performance without the need for more complex repairs.

The Lifespan of a Bolens BL160 Spark Plug

Understanding how long a spark plug typically lasts has helped me develop an effective maintenance schedule. While the manufacturer recommends replacement every 25-30 hours of operation, I’ve found that actual lifespan can vary significantly based on several factors.

In my experience, these conditions can reduce spark plug life:

1. Improper fuel mixture: When I accidentally mixed too much oil with my gasoline (going beyond the recommended 40:1 ratio), the plug fouled much more quickly than usual.
2. Low-quality fuel: Using fuel that had been sitting in my garage for months led to carbon buildup and shortened plug life.
3. Heavy-duty use: When I tackled an overgrown area that required extended periods at full throttle, the plug showed more wear afterward than during routine trimming.
4. Dusty conditions: Working in extremely dry, dusty areas seemed to accelerate plug fouling, likely due to debris entering the air intake.
5. Frequent cold starts: During fall cleanup, when I often start and stop the trimmer multiple times, the plug tends to accumulate more deposits.

Conversely, I’ve found these practices extend spark plug life:

1. Using fresh, high-quality fuel: I now mix smaller batches of fuel with premium gasoline and quality 2-cycle oil.
2. Proper warm-up: Allowing the engine to warm up for 30-60 seconds before use seems to reduce carbon buildup.
3. Regular air filter maintenance: Keeping the air filter clean prevents debris from entering the combustion chamber.
4. Running the tank dry before storage: This prevents fuel from evaporating and leaving deposits on the plug during storage.

By implementing these practices, I’ve occasionally extended my plug life beyond the recommended interval, though I still replace it annually as preventive maintenance.

Finding the Part Number for Your Bolens BL160 Spark Plug

When I first needed to replace my spark plug, I wasn’t sure how to identify the exact part I needed. After some research and consulting my owner’s manual, I discovered several ways to find this critical information.

The easiest method is checking the owner’s manual, where I found that the Bolens BL160 typically uses a Champion RCJ6Y spark plug or equivalent. If you’ve misplaced your manual, most manufacturers offer PDF versions online.

Another approach is to examine the old spark plug itself. Most have the part number stamped directly on the ceramic insulator. With a bit of cleaning, I was able to read “RCJ6Y” on my original plug, confirming what I found in the manual.

If both these methods fail, contacting Bolens customer service with your model number and serial number will get you the correct information. I’ve found their representatives to be helpful in identifying the proper parts.

For cross-reference purposes, I created a small chart in my maintenance notebook listing compatible plugs from different manufacturers:

• Champion RCJ6Y (original specification)
• NGK BPMR7A
• Torch L7RTC
• Bosch WSR6F

Having this information readily available has saved me time and prevented purchasing errors when shopping for replacements.

Conclusion: The Spark of Maintenance Wisdom

As I’ve journeyed through years of maintaining my Bolens BL160 string trimmer, I’ve come to appreciate the humble spark plug as perhaps the most crucial yet overlooked component. This tiny part, costing just a few dollars, can make the difference between a productive day of yard work and a frustrating experience with a machine that refuses to cooperate.

The spark plug is truly the heart of your string trimmer’s engine—it deserves attention, proper selection, and regular maintenance. Through trial and error, research, and plenty of hands-on experience, I’ve learned that this simple maintenance task pays dividends in reliability, performance, and longevity.

By following the guidelines I’ve shared—using the correct plug specifications, setting the proper gap, installing it correctly, and replacing it according to a regular schedule—you’ll likely avoid many of the common problems that plague small engine equipment.

I hope my experiences help you maintain your Bolens BL160 with confidence and keep it running strong season after season. Remember that a little attention to this small but mighty component can save you time, money, and frustration in the long run.

Now, if you’ll excuse me, I need to head outside—my perfectly maintained trimmer is waiting, and those edges won’t trim themselves!