MAINTENANCE: Trim Away

While there are no hard and fast rules to buying a string trimmer, there’s certainly one aspect that comes close: Make sure it’s still a joy to use at the end of a long day.
 
“Our guys tend to gravitate toward the lighter machines,” says Steve Rak Sr., owner of Southwest Landscape Management in Columbia Station, Ohio. “If an employee has a choice between a lighter, older machine or a newer, more powerful machine that might be heavier, they’ll pick the lighter machine every time.”
 
Through advancements by manufacturers, string trimmers are becoming more comfortable to use with almost every new model. String trimmers have come a long way from their mostly electric brethren to become high-powered gasoline units that offer versatility through a wide range of cutting heads. Through increased power-to-weight ratios, improved ergonomics, and operator-friendly controls, landscape contractors are more comfortable than ever during trimming tasks.
 
String trimmers are ideal for a number of applications, including trimming around hard-to-get-to areas, walkway/sidewalk edging or areas where mowers aren’t practical, such as steep terrain, ditches and small areas. Whether a trimmer employs anti-vibration technology, a 4-cycle or 2-cycle engine or an auto-feed line trimmer head, landscape contractors should consider the weight of the machine and how it will feel holding it after several hours.
  
Contractors should look for trimmers with the fewest internal moving parts as possible, says Jeff Nesom, product manager at Charlotte, N.C.-based Husqvarna. While many trimmers are still lightweight, to meet current emissions regulations, today’s models use technology that includes more internal moving parts. Those additional parts result in added weight and more maintenance, though string trimmers are likely to be the equipment needing the least maintenance.

BUYING TIPS. Landscape contractors must first assess the job at hand and determine the size of the project and the cutting attachments that will be needed before buying a trimmer.
   
Rak buys several of the same model trimmer. He’s found over the years that this saves time, money and training. “We buy them in uniform so we don’t have to buy different parts,” he says. “If I keep a box full of the same bump heads, employees will always get the right one, no matter what they pull out of the box. This uniformity makes a world of difference.”
 
Sixto Juarez, of DeSantis Landscapes, Salem, Ore., echoes that sentiment. “It should be easy to change the string,” he says. “There should be an easy way to show our crews how to change the heads so it takes them less time to do it in the field. Our crews used to spend a lot of time doing that.” That was, until the company began buying the same model trimmers.
 
Trimmer discussions inevitably lead to choosing the right engine. But regardless of the engine size and horsepower, the unit overall should have a good power-to-weight ratio.
 
“When it comes to looking for the right engine for line trimmers, 2-cycle engines offer the best power-to-weight ratios and contain a fewer number of moving parts, requiring less maintenance,” Nesom says. Contractors can experience excellent throttle response and good power on engines with 25-30cc (minimum 1.2-horsepower) engines. “We get as big an engine we can get in the lightest machine,” Rak says. For large commercial properties with heavy applications, 30cc and greater (with a minimum 1.8-horsepower) are suggested.
 
Accessories such as harnesses go a long way to reducing operator fatigue by taking stress off the arms, Juarez says. “At the end of a long day, it can get very tiring,” he says. “Without something like a harness, your arms can hurt quite a bit.”
 
Like many products, operator comfort for string trimmers is evolving. “When trimmers first came out, there wasn’t a major concern about weight,” says Marv Mathwig, a product manager for Virginia Beach, Va.-based STIHL. “Now there is, so they’re lighter. Units in the past vibrated a lot and there weren’t anti-vibration components. The equipment has definitely gotten more fuel-efficient.” Part of that fuel efficiency is derived from the development of new technologies to comply with emissions regulations.
 
Four-cycle and 2-cycle engines employ different technologies to comply with emissions standards. Two-cycle engines burn a fuel-oil mixture, while 4-cycles models use a separate oil reservoir. Four-cycles fire every other revolution, which allows the engine to burn cleaner and at a lower temperature, while 2-cycles fire each revolution. “How much should the landscape contractor pay attention to that? Probably not much,” Mathwig says. “I wouldn’t make the decision to buy a trimmer just on 4-cycle or 2-cycle.”
 
Along with advancements in other areas, string trimmers have become safer machines. All trimmers produced today are required to provide a deflector type of cutting shield that surrounds the cutting attachment, Nesom says. Cutting shields reduce the chance of rocks, trimmings and other projectiles from striking nearby property, people or pets. In addition, spark arrestors control the muffler output and reduce the potential for fires due to sparks. Interlocks on the throttle also prevent unintended throttle engagement. Heat protection that surrounds the muffler and engine housing reduces the chance of burns to the operator. Most manufacturers provide a simple on/off switch to shut down the engine in an emergency.
 
Operators are warned to wear protective clothing, including eye, ear and leg protection.
 
“Definitely a must is proper eye protection,” Mathwig says. “We recommend a steel toe in a shoe or boot that has excellent traction to reduce the chance of slipping.”
 
Safety apparel should also include heavy-duty non-slip gloves and sturdy, snug-fitting clothing. Mathwig recommends operators read the user manual, even if they’ve used string trimmers in the past. The manual spells out details about safe operation that the user may not have thought about. For example, if the operator intends to use a cutting blade, a different deflector is more appropriate than the one used in conjunction with a string cutting head.
 
While string trimmers have become more technologically advanced and versatile, there are some applications they’re not meant to tackle. String trimmers are not designed for brush cutting, heavy edging applications or hedge trimming.

KEEPING THEM TRIMMING. Maintenance requirements for string trimmers vary depending on workload and conditions. Extreme conditions may require a higher frequency of replacing normal maintenance items. Some 4-cycle products require regular oil changes and engine valve adjustments. “A common maintenance item is the air filter,” Mathwig says. “If the engine starts to bog down or you notice you’re not getting the performance you’ve gotten in the past, and you operate often in dusty conditions, you’ll probably want to start off by cleaning the air filter.”
 
The carburetor is another component that may require occasional idle adjustment. And if the trimmer features a gear box for the cutting heads, a weekly check should ensure there’s enough grease in the gearbox. And depending on usage, the engine’s fuel filter will need to be replaced at least on an annual basis.
 
Rak uses a high-quality synthetic oil in his string trimmers, which he believes makes them last longer. Just as the maintenance requirements are subject to use and conditions, these factors will determine the lifespan of the equipment.
 
“Contractors can expect a trimmer that’s subjected to constant work to still last more than a year,” Mathwig says. “If these guys are taking care of the equipment by maintaining it, it could be replaced between two and five years.” Trimmers should last long after the EPA’s emissions durability and expected useful life rating has been met or exceeded. Experts say contractors should stay away from machines that display useful life ratings of 50 hours, because those are for consumer use.
 
“The lifespan of a commercial trimmer depends on the conditions in which the trimmer is operated and how much routine maintenance was performed on the unit,” Nesom says.   

Most contractors expect a commercial trimmer to last between 900 to 1,200 hours or more with proper care. Contractors can get a durable, commercial-grade string trimmer for a few hundred dollars. In many cases, people just want raw power. A contractor requiring more than 2 horsepower can expect to pay up to $500. A trimmer in the 1.25-horsepower range will cost around $300.