when 800 mm blades are used. For performingaerobatics, it is better to get the standard <strong>Benzin</strong>Acrobatic kit and the 725 mm carbon blades. Thehelicopter kits include fiberglass tail rotor blades butnot main rotor blades. East Coast Vario(www.eastcoastvario.com) has 725 mm long, symmetricalairfoil, carbon blades designed specifically for thishelicopter. It is important to use these blades and notnormal 710 or 720 mm blades from 90-size helicoptermodels. Vario’s 725 mm blades have a wider chord thanthe 710 and 720 mm blades. The wide chord isnecessary to generate the lift required to propel this14-pound model. If regular 710 or 720 mm blades areused, the helicopter will feel underpowered.The model can easily perform loops and rolls. Incapable hands, it can perform challenging 3-D stunts likePiro flips, Funnels, Tail Slides, etc. but at a slowed downpace. For example, with a Freya or a Raptor, usually onecomplete Chaos cycle (one upright 360 Pirouette with aflip into inverted Pirouette and back to the uprightposition again) takes 1 to 2 seconds, but with the <strong>Benzin</strong>,it takes about 3 to 4 seconds. Of course, the 14-pound<strong>Benzin</strong> cannot match the agility of lighter 90-sizehelicopters. For example, the <strong>Benzin</strong> is not good atdoing Tick-Tocks or Collective Shuffles, which require atremendous power-to-weight ratio. However, the huge<strong>Benzin</strong> is fantastic at performing large and gracefulmaneuvers. When the <strong>Benzin</strong> trucks down the runwayat 60 mph and does a slow roll ten feet off the deck, itis an impressive sight.The <strong>Benzin</strong> Acrobatic is very stable in flight whenflybar weights or heavier paddles are used. The modelsits there steady, in hover, like a sleepinggiant. On its first flight, the <strong>Benzin</strong>Acrobatic showed no tail fin shaking orvibration. The engine ran silky smooth andthe main rotor blades required no balancing.Not sure if we were just lucky, or all Zenoah23 cc engines from East Coast Vario comethis well balanced. Instead of using gasolinefrom a gas station, my local group prefersusing Coleman brand kerosene lantern fuelmixed with three percent 2-strokemotorcycle oil. The best oil that my friendand I have found is the Castor 927 highperformance 2-cycle oil produced by MaximaRacing Lubricant in Santee, California. Seewww.maximausa.com.We like Coleman kerosene instead ofregular automobile gasoline because kerosenemakes the engine run clean with no smoke andthe engine sings at a constant note, with nodetonation. Try it and you will discover itworks better than gasoline. It is moreexpensive than gasoline, but still cheaper thanglow fuel. Our mixture of Coleman fuelprovides a longer flying time than glow fuel because itonly contains 3 percent oil, while typical 30% nitro glowfuel contains 30% nitromethane, 20% oil, and only 50%methanol alcohol. Alcohol is what provides the energy,the oil is only for lubrication and causes smoke, and thenitromethane is an oxidizer to give power. In a keroseneor gasoline mixture, 97% is fuel and only 3% is oil. The<strong>Benzin</strong> Acrobatic can easily fly for 30 minutes, nonstop,on one fill. In addition, there is no greasy residue towipe off. A gasoline engine powered helicopter kitROTORY53
maybe expensive to purchase, but it saves fuel costs.The Zenoah 23 cc engine is slightly cheaper than a YS91 or OS 91 engine. The Vario <strong>Benzin</strong> muffler at $261is more expensive than mufflers for the YS 91 or OS91. On the other hand, there is no need for anelectric starter or glow battery. The trick to startthis gasoline engine is to choke the engine by fullyclosing the carburetor opening then, pull the recoilstarter twice. Then open the carburetor slightly andthe engine will start on the next pull.I highly recommend buying the plastic Quick 2 Mixplastic mixer bottle from Maxima. This plastic bottlehas a scale printed on the back of the bottle to allowyou to get any mixture ratio you want. For a brandnew engine, it is best to use the 32 to 1 ratio shown onthe bottle. That means, pour 32 parts of kerosenefuel to one part of oil into this bottle, then close thecap and shake it like a Martini for few seconds. I needto repeat this process a few times to fill up a onegalloncontainer, which I carry to the flying field.If you do decide to get a gas helicopter, make sureto purchase some Tygon gasoline fuel line, special fuelfilter, a canister designed for gasoline, and a handcrank pump designed for petrol fuel. Standard siliconefuel line for glow engines will not work. Joe Howard ofEast Coast Vario will be happy to explain what itemsyou require. Sullivan Products in Maryland makes avery high quality hand pump for gasoline fuel andkerosene.To learn more about the <strong>Benzin</strong> Acrobatic, go towww.eastcoastvario.com and order a hard copy of the2005 Vario catalog. This full color catalog is 51454ROTORY
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