In-house Engine Maintenance

By Nigel Miller

A majority of the commercial landscape equipment brought to a dealer service shop for engine repair doesn’t need to be there in the first place. Many engine issues that are sent to a service technician like me could be fixed by the commercial landscapers themselves or, more typically, prevented from initially occurring by following some basic preventative-maintenance protocol.

Whether it’s a blower, pull saw, string trimmer, backpack blower or a larger piece of equipment such as a zero-turn mower, keeping equipment out of the shop and on the lawn can save your company quite a bit — sometimes hundreds of dollars per visit. In fact, an hour’s worth of labor without the cost of replacement parts can average $100 at some service shops. Simply bringing in a handheld piece of equipment to our shop, A-1 Outdoor Power, for inspection will cost $34.50 when the fix itself could have been done by the contractor for a couple of bucks. And in an economy slow to turn around, you already know every dollar counts.

The following are a few of the more common engine service requests I see throughout the lawn care season and how to prevent them.

Quality-of-cut issues for zero-turn mowers

Every year in late spring and early summer, as grass conditions change, our shop sees its share of lawn care contractors bring in their zero-turn mowers experiencing quality-of-cut issues. If the mower’s clippings are clumping when it’s running with a mulch kit, often there is nothing wrong at all with the mower. It’s typically an operator who’s trying to cut more grass than the mower can handle.

The fix is likely as simple as adhering to the “one-third rule.” That is, never cut more than one-third of the grass length up to one inch in a single pass, especially when the ground is damp and the grass is more prone to clumping. This can occur when a contractor is trying to mow a property in one pass. Sometimes to do it right and get a quality cut, two passes are required.

We also see a lot of customers complaining that their zero-turn mowers are cutting unevenly. For example, the customer will say the mower is cutting low on the right front side of the mower deck. The first question I ask them is if they’ve checked their tire pressure lately. Nine times out of 10 their mower is in perfectly good condition, except their right-rear tire pressure is low, causing an uneven cut.

A clean air filter is key

The lifeline to a steady-running engine is a clean air filter. Without it, your equipment’s power source can heat up and break down fast.

We see a lot of customers bringing in their equipment with engines that are “running rich.” That occurs when the engine’s air filter is so clogged with debris that the engine can’t draw any air through the filter, so it naturally tries to draw air through the crank case. That increases the crank case vacuum pressure and causes oil to be pulled into the combustion chamber, causing engine damage.

Typical warning signs to look for include engine smoke and an engine burning an excessive amount of oil. Also, if you see any spots on the engine where oil is seeping out, you may be on your way to overheating the engine.

You can determine when your engine is seeping oil because dirt and debris particles will start to clump where the sticky oil is seeping out onto the engine case.

Ignoring a clogged filter can wreak havoc on your engine. It can damage crank shaft seals, closure plate gaskets and could even take out a head gasket — all very expensive repairs. Operate a rich-running engine too long, and you may find yourself in the market for a new engine altogether — costing upwards of $1,500. Fortunately, you can fix the problem yourself for about $10 with almost no downtime to your equipment.


The degree of difficulty in changing the air filter on your equipment will differ depending on the type of engine you’re operating, because access and user-friendliness of an engine differs. Although all engine manufacturers have their strengths, Vanguard engines are typically very user-friendly. For example, this potentially disastrous problem is an extremely easy fix on Vanguard engines because it only requires the loosening of one screw to get to the air filter.

Handheld equipment won’t throttle up after storage

When handheld equipment with a plastic gas tank is used for the first time after storage or after simply sitting for a long period of time, you may find it difficult to throttle up the engine.

Photos courtesy of A-1 Outdoor Power. Photos provided by Briggs & Stratton Commercial Power.

Before you bring it to a professional service technician, do yourself a favor and check the fuel filter. If the fuel filter has even the smallest bit of dry fuel on it — which can easily occur after a period with little to no use — it can be tough to throttle.

This is one of those classic problems that can be a simple fix. But because the fuel filter is located out of direct sight in the gas tank, many contractors assume it can’t be fixed without professional help.

Here’s the simple solution: run the gas tank dry in the fall before winter storage. Then, as the engine is still hot, change the oil and replace the fuel filter. Doing this while the engine is still hot helps the oil mix to flow better and keep the impurities suspended in the oil. Just be careful when handling that hot engine and oil.

Keep the critters away

Blowing off all the grass in and around your equipment’s engine can go a long way to preventing costly downtime and expensive repair bills. Those tiny piles of grass in the nooks and crannies around an engine are inviting places for rodents to nest. They routinely build nests on your engine’s cylinders. If the nest isn’t cleaned out your engine is prone to overheat, leak oil and even damage the cooling system.

Mice are also prone to chewing through the sheathing that protects the wiring of the engine’s cooling system. A basic cooling system cleaning can run upwards of $50, when all a contractor has to do is take the engine shroud off and blow the grass away from the fixtures.

If oil leaks need fixing and wiring damage needs repair, it can take anywhere from 2.5 to 4 hours to repair, because the work requires the engine to be pulled out. So just keeping the grass build-up that comes with daily lawn care work off the engine can save potentially hundreds of dollars in repairs.

Nigel Miller is a service technician at A-1 Outdoor Power in Corcoran, Minn. He has more than a decade of industry experience working with small engines.

Article provided by Briggs & Stratton Commercial Power.

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