A little preventative maintenance goes a long way in keeping your welder/generator in top shape. Proper maintenance extends engine/welder life, ensures peak performance at all times, maintains reliability/avoiding costly breakdowns, prevents voiding warranty coverage, and maximizes resale value. Unfortunately, up to half of all engine-drive owners don’t follow proper maintenance procedures. The information below will shed more light on the consequences of poor maintenance and inspire better care.
Read the Manual
Read the owner’s manual cover-to-cover and familiarize yourself with your engine drive to properly maintain your machine.
The Lifeblood of Your Engine
Oil is necessary to lubricate the internal components of the engine, dissipate heat and prevent corrosion. Running your engine with low oil will damage the engine and eventually result in failure. Motor oil is available in a variety of brands, grades and viscosity. Use a multi-viscosity, SAE SJ grade or better oil.
Perform Regular Oil Changes and Understand the Importance of Oil Level
Miller and Kohler recommend oil changes every 100 hours to maintain optimum performance. Whenever you change your motor oil, put in the correct amount: do
not over- or under-fill. If you over-fill the engine, it may reduce generator power and welding output. In addition, too much oil may lead to fuel pump failure.
Under-filling your engine can lead to catastrophic engine failure. Damage caused by insufficient oil is considered owner neglect and is not covered by warranty. To correctly check the oil level on a Miller engine-drive with a Kohler engine, clean the dipstick, drop it in and twist it backwards until it “falls down” on the thread. While you might want to instinctively screw the cap down, don’t do it.
Check the Oil Filter
An oil filter removes metallic particles and other contaminants from the oil. Kohler recommends changing your oil filter every 200 hours (or every other oil change). If you don’t regularly change the filter, it eventually becomes clogged with impurities that restrict oil flow. Dirty oil causes premature wear on the engine’s bearing surfaces. Bottom line, change the oil filter.
Fuel for Energy
Always use clean, fresh fuel. When stale fuel is burned, it creates varnish that gums up the carburetor. Problems caused by stale fuel use aren’t covered under warranty. Fuel stays fresh for about three months (less for reformulated gasoline that has 10 percent ethanol). If you don’t plan to use your engine drive for more than 90 days, add a fuel stabilizer at the same time you fill up.
People who use an engine drive for emergency generator power should especially heed this advice. There is a huge misconception about stabilizer refreshing stale fuel. It doesn’t. It only helps fuel from going stale. Another danger of using old fuel is that it might not be the right seasonal blend.
A Cold Weather Note
Consider installing an anti-icing kit (for winter months) which solves problems with carburetor icing.
Never use E85 in Kohler Command or any other carbureted engine.
The large amount of ethanol attacks and corrodes the rubber, brass and aluminum fittings within the carburetor and will ruin the engine in just 15 minutes. Reformulated gas is okay to use in all Kohler carbureted engines, but will be less energy-efficient than 100 percent gas.
The Fuel Filter
The fuel filter should be replaced every 200 hours or any time that you suspect that you’ve filled up the tank with a bad batch of gas. If the filter gets too dirty, it will restrict the amount of fuel that travels to the carburetor, which results in a “lean” air/fuel ratio. The lean ratio will inevitably reduce the generator power available and lower welding output.
Replace the Air Filter
At the very minimum, replace the air filter every 200 hours and more frequently if you use your welder generator in extremely dirty and dusty environments. An extremely dirty air filter prevents the proper amount of air from reaching the carburetor. As a result, the engine runs “rich” (too much fuel and not enough air), which fouls the spark plugs and reduces generator output and power at the arc.
Air filter problems are a leading cause of warranty claims. In fact, if a filter becomes too clogged, it creates a huge vacuum draw that pulls dirt into the system through any crack available. Dirt can get pulled into the fuel system, work its way into the cylinder and erode the cylinder walls.
To keep your machine running cool, use compressed air to blow out the fan and
the cooling fins every 100 hours. It’s a good idea to get into the habit of cleaning out the cooling system every time you change the oil. If the fan cannot adequately cool the motor, the unit will overheat and eventually shut down. If your engine drive has been sitting idle for a while, look inside for mouse nests or rodent building materials. This is a common problem with engine drives stored in barns, sheds or under porches.
The Spark within the System
To ensure that the spark plugs continue to provide reliable ignition, replace the spark plugs every 500 hours. The distance between the spark plug’s electrode and tang plays a vital role in reliable ignition. Refer to your engine’s owner’s manual to determine the optimum gap.
By examining the condition of the spark plugs, you can also determine if your machine is running too rich or too lean. A spark plug covered with a white coating indicates that the engine is running too lean, which could mean you have a clogged or dirty fuel filter. Conversely, a spark plug covered with soot means that the engine is running too rich and you should check or clean the air filter. To clean a dirty spark plug, remove the soot with a wire brush.
Miller factory sets and tests each engine drive for an idle speed of 2400 rpm (and a run speed of 3700 rpm). A fast idle speed won’t cause any problems, but it wastes fuel and creates more noise. An idle speed lower than 2350 rpm could cause the engine to bog down when you try to strike an arc or put a heavy motor load on it. The engine will have a harder time coming up to appropriate speed, so checking the idle is very important for good performance.
For more maintenance information, visit www.MillerWelds.com/products/generators.