RC Engine Maintenance: Seasonal Shutdown Tips and Long-Term Storage

As the weather gets colder and the flying season slows down, some of our airplanes will inevitably make their way to the basement, workshop, garage, or wherever they spend the winter.

After that last flight of the season, it’s tempting to wipe down the airplane, put it away, and figure you’ll deal with everything in the spring.

Unfortunately, your engine may have other ideas.

A little maintenance before long-term storage can help prevent corrosion, hardened fuel lines, fuel-system problems, and that frustrating spring afternoon when everyone else is flying while you’re at the bench trying to figure out why an engine that ran perfectly last fall suddenly won’t cooperate.

Spring maintenance really begins when you put the airplane away in the fall.

Start With a Good Cleaning

Before putting an airplane away for several months, give the engine and surrounding area a good cleaning.

Glow-powered airplanes are particularly good at coating themselves with oil and exhaust residue. Gas models aren’t necessarily spotless either. Remove the accumulated oil, dirt, grass, and grime from around the engine, muffler, firewall, and landing gear.

Besides making the airplane look better, cleaning gives you a chance to inspect everything closely. A loose muffler bolt, cracked fuel line, damaged engine mount, or loose firewall is much easier to notice when it isn’t hiding underneath a season’s worth of residue.

It’s also much nicer to pull a clean airplane off the rack next spring than one that’s been sitting all winter covered in last October’s exhaust oil.

Glow Engines Need Special Attention

Glow engines deserve particular attention before long-term storage because of the fuel they use.

Glow fuel typically contains methanol, which can attract moisture. Moisture inside an engine isn’t something you want sitting there for several months because it can contribute to internal corrosion.

At the end of your final flying session, remove or use up the fuel remaining in the tank and fuel lines according to the recommendations for your particular engine and fuel system.

After the engine has cooled, many glow-engine manufacturers recommend using an appropriate after-run oil for long-term storage. Follow the engine manufacturer’s instructions on the type of oil, how much to use, and where to apply it.

After-run oil can help protect internal metal surfaces from corrosion while the engine is sitting unused.

This is one of those little jobs that takes only a few minutes but can make a big difference when you pull the airplane out again months later.

Gas Engines Are Different

Gasoline engines have different storage requirements, and following the engine and carburetor manufacturer’s recommendations matters.

Depending on the engine, fuel system, and storage length, the recommendation may be to remove the fuel, use properly stabilized fuel, or follow another specific storage procedure.

Avoid assuming that every gasoline engine should simply be run completely dry. Carburetors, diaphragms, fuel lines, and other components can have different requirements, and what is appropriate for one system isn’t necessarily best for another.

If you’re using fuel stabilizer, make sure it is compatible with your fuel and engine and follow the manufacturer’s directions for the proper amount.

The important thing is not to leave questionable old fuel sitting in the airplane for months and then expect everything to work perfectly in the spring.

Inspect the Fuel Tank and Lines

Whether you’re flying glow or gas, the end of the season is an excellent time to inspect the entire fuel system.

Look at the fuel tubing for cracks, stiffness, discoloration, swelling, or anything else that suggests deterioration.

Check the tank stopper, fittings, filters, vents, and fuel connections. If you can easily inspect the clunk and internal tubing, check those as well.

Fuel tubing doesn’t last forever.

If something looks questionable now, replacing it in winter is much easier than discovering the problem after an engine quits on takeoff next spring.

Take a Look at the Carburetor and Linkage

Operate the throttle and choke linkages and make sure everything moves smoothly.

Check the servo connections, control rods, ball links, clevises, and other hardware associated with the engine controls.

Look around the carburetor for dirt, residue, or signs of fuel leakage.

If something feels sticky or doesn’t move as freely as it should, now is the time to find out why.

Several months of sitting probably won’t fix it.

Check the Glow Plug or Spark Plug

The end of the flying season is also a convenient time to inspect the plug.

For a glow engine, remove the glow plug and inspect its condition. If it has seen a lot of use or looks questionable, replacing it before the next season is inexpensive insurance.

For a gasoline engine, inspect the spark plug according to the engine manufacturer’s recommendations. Its condition can sometimes tell you something about how the engine has been running.

If the plug needs replacing, note the correct replacement—or, better yet, have one ready before spring.

Check the Engine Mount and Firewall

Since you’re already working around the engine, take a few minutes to inspect how it’s attached to the airplane.

Check the engine mounting bolts, motor mount, firewall, muffler, and exhaust system.

Look for cracks, loose hardware, separated glue joints, or anything that has shifted during the flying season.

Give the engine a gentle check for movement. If something moves that shouldn’t, investigate it before the airplane goes into storage.

Remember, vibration has had an entire flying season to work on all those screws and bolts.

Inspect the Propeller and Spinner

This is also a perfect opportunity to inspect the propeller and spinner.

Look closely for cracks, chips, nicks, damaged mounting holes, or anything else that might make the propeller unsafe.

Check the spinner and back plate for cracks or distortion.

If something needs replacing, write it down or replace it now. Don’t put a questionable propeller back on the airplane and assume you’ll remember it five months from now.

Don’t Forget the Batteries

Gas and glow airplanes often have receiver batteries, and gas models may also have a separate ignition battery.

Don’t put the airplane away for several months and forget about the batteries.

Different battery chemistries have different storage and maintenance requirements. Follow the battery manufacturer’s recommendations regarding storage charge, periodic charging, or other long-term maintenance.

Also inspect the battery packs, connectors, switches, and wiring for damage or corrosion.

If a battery is getting old or showing signs that it isn’t holding capacity the way it once did, winter is a good time to replace it.

Where You Store the Airplane Matters

If possible, store the airplane in a dry location that doesn’t experience extreme temperature swings.

Moisture and condensation are enemies of engines, electronics, hardware, and airframes.

An unheated building may be perfectly workable depending on conditions, but damp environments deserve extra consideration. Keeping the airplane dry is more important than keeping it particularly warm.

Also consider covering the engine or entire airplane to keep dust from accumulating while still avoiding anything that could trap moisture.

Make Yourself a Spring To-Do List

Here’s one of the easiest maintenance tricks of all.

Write things down.

If the airplane needs a new fuel line, glow plug, spark plug, battery, propeller, wheel, servo, or anything else, make a note and keep it with the airplane—or take care of it during the winter.

It may seem impossible that you’ll forget something obvious.

You will.

After several months and several other airplanes, that little problem you were absolutely certain you’d remember may be long gone from your memory.

If you put an airplane away in October with a problem, there’s an excellent chance it’ll still have that problem in April.

A Little Work Now Means More Flying Later

None of this requires spending an entire weekend tearing every engine apart.

For most airplanes, we’re talking about some basic cleaning, inspection, proper fuel-system preparation, corrosion protection where appropriate, and taking care of anything that already needs attention.

The payoff comes several months later.

That first beautiful spring flying day eventually arrives. The sun is out, the wind is light, and airplanes start showing up at the field.

That’s when you’ll appreciate the time you spent taking care of things before winter.

Instead of sitting at the workbench cleaning a carburetor, replacing a rotten fuel line, or wondering why the engine won’t start, you can be at the flight line doing what you came there to do.

Fly.

Take care of your engines when you put them away, and they’ll be much more likely to be ready when you are.

Happy and safe flying from the York Area Radio Control Club!