Once you’ve mastered the basics with foamies and smaller electrics, it’s time to step into the serious side of 3D flying — the world of big gas motors. This is where the roar of a tuned engine, the smell of premix, and the raw torque of a 100+cc powerhouse come into play. But choosing the right gas engine and getting it properly tuned is a critical step that can make or break your flying experience.
Choosing the Right Engine
When you’re picking your first big gas motor, consider the following:
🛩 Size Matters
For a 35% scale airframe (around 100–106″), you’ll want something in the 100cc to 120cc range. DA (Desert Aircraft), GP, DLE, and EME are all solid names with proven track records.
🔧 Support & Parts Availability
Go with a brand that has good support in the U.S. and readily available parts. If you’re going to be flying often, odds are you’ll eventually need bearings, reeds, or even a new ignition.
🎯 Performance vs. Price
Desert Aircraft motors are top-tier for power, reliability, and smoothness — but they carry a premium. GP engines give excellent bang-for-the-buck if you’re okay doing a little more tuning. DLE is budget-friendly and great for getting started without spending top dollar.
🔥 Twin vs. Single Cylinder
For planes this size, twins are the way to go. They’re smoother, better balanced, and easier on your airframe — especially with big props and hard 3D flying.
Tuning Tips
You don’t want to just bolt it on and go — proper tuning is everything. Here’s what you need to know:
🧪 Break It In Right
Follow your engine manufacturer’s break-in procedure. Don’t just hover around the pits revving it up. Get it in the air and fly gentle, rich, and smooth flights at first.
🛠Tune for the Air
Idle and transition tuning should be done on the ground, but you need to do high-speed needle tuning in the air under load. Listen for sagging RPMs or lean popping.
⛽ Fuel Mix
Use a high-quality synthetic oil (like Redline or Stihl HP Ultra) at around 32:1 or 40:1, depending on the motor. Ethanol-free gas is preferred, but premium pump gas works fine if you fly regularly.
💨 Check for Leaks
Every time you fill the tank, check your fuel lines, clunk, and fittings. Air leaks will mess with your tuning fast.
🔊 Prop and Muffler Choice
A good prop (like a Falcon 27×10 or Mejzlik 28×9) makes a huge difference in throttle response. Pair it with a tuned canister or high-flow muffler for that sweet, crisp throttle punch.
Pro Tip: Bring a Tach and a Friend
A handheld tachometer is your best friend during tuning. Better yet, have a buddy help — one watches temps and listens, the other flies and gives feedback. Together, you’ll get that engine running like a champ.
You’re not truly in the game until you’re flying a big gasser tuned to perfection, shaking the ground and tearing up the sky. Once you’ve got that dialed-in DA or GP screaming on knife edge inches from the deck, you’ll know — this is what 3D flying is all about.
Want a walkthrough of mounting, setting up ignition kills, or radio setup for a big gas plane? Let me know and I’ll write up a guide!
