Cold Weather Engine Starts — in 10 Easy Steps

Oct 29, 2013 22 Comments by

While it may not yet be as frigid as it seems in the photo above, the frost is definitely on the pumpkin! As the weather turns colder, it’s a good time to revisit some cold-engine starting techniques. Have some tips for flying in colder conditions? Leave them in the comments section!


1. Turn on your transmitter and receiver.

2. Fully open the throttle.

3. Watch for fuel in the line and cover the throttle opening with your finger. Firmly grip the propeller, and rotate it until the fuel is just up to the carb. Don’t flip it! Now turn the prop over–twice, if it’s warmer than 50 degrees F; three times, if it’s colder–to prime the engine.

4. With the glow plug disconnected, flip the engine over six to eight times.

5. Close the throttle and move the trim to fully up. This should open the throttle barrel a little more. The throttle should be about 1/4 open.

6. Grab the prop firmly, and rotate the engine until it passes through the compression part of the stroke. You should feel the engine “kick.” If it does, it will now start on the first or second flip. Always use a chicken stick or electric starter for starting. If the engine doesn’t start, flip the prop a few times with the glow plug disconnected, and try again. If it doesn’t kick now, choke it one more time with the throttle fully open, flip the prop a few more times, reposition the throttle, light the glow plug, and try again.

7. If, when your engine starts, it just revs up and quits, turn the high-speed needle valve 1/2 turn counterclockwise to open it, and try again. Repeat this if necessary.

8. If the engine starts, slows down and quits, and if a lot of smoke comes out of the exhaust, turn the high-speed needle valve clockwise to make the mixture leaner, 1/4 turn at a time. Restart the engine.

9. When the engine has started, hold the throttle partially open, and let the engine warm up for at least one minute before making the final adjustments.

10. Most engines are harder to start when they’re hot. To start a hot engine, draw the fuel up to the carb, but don’t choke or prime it. Open the throttle to 1/4. Flip the prop hard. Use and electric starter, if you have one available.

Debra Cleghorn, Featured News

About the author

Model Airplane News Executive editor. About me: I’m a publishing professional who has a passion for aviation and RC, and I love creating issues, books and a website that help RC pilots to enjoy this sport even more. I admire scale aircraft and enjoy the convenience of flying smaller electrics.

22 Responses to “Cold Weather Engine Starts — in 10 Easy Steps”

  1. Daveymac says:

    I earned my all seasons patch while in northern Minnesota – flew nitro planes at -20 degrees F. One trick is to use chemical hand warmers wrapped around the head and covered with a towel to keep the engine warm. Another is to use higher nitro % than in warm weather.

  2. Brian WINCH says:

    If you replace 10% methanol with 10% petrol in the fuel, very cold weather starts are much easier as the petrol will vaporize much quicker than methanol. No harm to your engine – works very well. You can leave out the nitro if you wish as the petrol assists both starting and steady idle.

    • mohammad reza says:

      thanks brian for your comment . but i didn’t get it .
      are you mean we can use methanol fuel contain 10% petrol instead of 10% nitro ?
      or we should add 10% petrol to the methanol fuel which has also 10% nitro .

  3. Daveymac says:

    Clarification: the hand warmer and towel is only for before first flight and BETWEEN flights…not WHILE flying. lol

  4. Terry Bolin says:

    When in the very cold air, We always give a few drops of lighter fluid in venturi and flip the motor over.. they start very quick and draw fuel to keep running so its pretty effortless…

  5. Terry Bolin says:

    cigerette kighter fluid…

  6. Bill says:

    When do I take my finger off the carb as indicated in step three….half way through step 3, at the end of step 3 or end of step 4 ???


  7. Daryl McRoberts says:

    Our club here in Alaska flies year round. Our coldest event so far was -31 F. One way to preheat an engine is to place the spinner in the exhaust pipe of a running car or pickup for 15 minutes or so. Another is to use a propane torch on the head if you can reach it. Electrics always start but the battery can be damaged at extreme temperatures.


  8. Daryl McRoberts says:

    Our club in Alaska flys year round. Our coldest event was -31 degrees. To preheat an engine you can put the spinner in the exhaust pipe of a car or pickup for 15 minutes or so. Or you can use a propane torch on the cylinder if you can reach it. Electrics always start, but you can ruin a battery if it is to cold.

  9. Chuck says:

    Bill, At the end.

  10. David Pierce says:

    Thanks for this article, had to do one of these yesterday at 40 degrees. Not too hard but they don’t like cold weather much!

  11. چگونه در هوای سرد موتور هواپیمای خود را روشن کنیم | RC Data says:

    [...] ۱۰ Steps to a Quick Cold Start [...]

  12. Don Williams says:

    Thanks, how about starting electrics in cold weather? Any tips? Thanks. Don

  13. Don mielke says:

    Who makes that plane?

  14. Marcelo says:

    …one of the best planes to fly in any temperature, wheather or place in all the world, love those skies, have one same colors with a 45 4st max engine 0% fuel and a same color 36 Zenoah gas engine, sorry…congrats to all aeromodelists…

  15. Dennis Doiron says:

    You forgot one more great tip; live in a warm climate like Florida!

  16. Paul Whiteman says:

    I love to fly in the winter off the lake…So much fun. I use the towel method to keep the heat in on first and subsequent flghts and will take a cooler which is actaully a heater in the winter and keep my fuel and radio / radio bag in it with a heat pack (like for your kneck). The warm fuel helps the start and the toasty radio and radio bag helps you fly more comfortable. It is not just all about is the comfort and safety level as well:) Oh..built a ski style starter table too which keeps you off the ground…that helps with the rest of your body. Gettin cold here in Canada now so the ice flyin will start soon and can’t wait! PWW

  17. Daryl McRoberts says:

    Step 3′s reference to 50* leads me to think the author is from Florida:-)
    That is not close to cold.

  18. Joe Willert says:

    Lighter fluid works great as a primer for your first cold weather start.

  19. chris says:

    pre heat… biggest thing needed to start nitro’s in the cold

  20. Gary Robertson says:

    For Glow Fuel engines, use lighter fluid prime. Keep glow-starter batteries in your inside pocket.
    Put Tx in a Tx bag (Hobby King have a great Turnigy unit), along with a hand-warmer pouch (start the pouch at home…they take a while to get going). Cut-down slip-on pencil erasers slipped over the sticks really help keep thumbs from freezing in contact with the cold and sharp sticks! Finally you may have to adjust the carb settings…the alcohol/lube fuel gets a lot thicker as it cools off below freezing.

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