Twist and evolution 46 dead sticking after 2-4 mins into flight.
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Twist and evolution 46 dead sticking after 2-4 mins into flight.
Hey all I have the 40 size twist with a evo 46 motor and I have dead sticks .First off the motor is running top notch at idle and full throttle. Does not load up at idle, and full rpm at WOT. If I fly normal , like tight loops, inverted circles, ovals figure 8's stuff like that the plane runs fine. It happens after 2-4 mins into flight and when I do a very big loop at half throttle, when the plane reaches the crest of the loop I throttle back to 3-5 clicks from idle. The plane is inverted at this time . When the plane starts on the downward attitude, maybe a 3-5 second downward run to finish the loop it will dead stick. It may be starving for fuel . The clunk is out of the fuel for to long and runs out of fuel even though the tank is 3/4 full . This is only a theory but I am going to run a simulation on an engine stand to see if this proves true.I replaced the entire fuel set up ,tank ,tubes clunks and added a filter. Still it dead dticks.The twist is a very slow flier and I think it is starving for fuel on the downward run. Now when I send it up to a very high altitude and point the nose down and spiral down for a long time it does not dead stick. But the high "G" load on everything may keep the fuel and clunk together keeping it from starving. What are your thoughts on this?
#2
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RE: Twist and evolution 46 dead sticking after 2-4 mins into flight.
Leaning out during g's is normally caused by running too lean. Open the needle up 3 or 4 clicks.
You have to set the needle valve slightly rich on take off because the engine runs leaner and leaner as the flight goes on. If you set for max power on take off, you'll be too lean some time later, depending on how lean you set it. You should be leaving a slight smoke trail after take off.
You have to set the needle valve slightly rich on take off because the engine runs leaner and leaner as the flight goes on. If you set for max power on take off, you'll be too lean some time later, depending on how lean you set it. You should be leaving a slight smoke trail after take off.
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RE: Twist and evolution 46 dead sticking after 2-4 mins into flight.
Yes, you're right. I don't have it too lean . It is making good smoke through all rpm levels. A Great Guy at our club ,who is fantastic with engines fine tuned it yesterday. We spent all afternoon adjusting the low set and high set so it would purr through all levels of flight. The low set will idle for a good minute and when you hit the throttle it will bark at you with out loading up. The high set was adjusted till it leand out and was backed off so it runs just a little rich and it makes nice smoke. I don't think its a high or low set adjustment but anything is possable. One other thing I failed to post earlier was I have the baffle plate removed in the muffler. That may be a symptom . I ran a test a few minutes ago with a full tank, and everything in the plane except the wing. I placed the radio throttle stick 2 clicks below half and ran it in a simulated loop. Everything ran fine till 2 minutes into the test, while inverted, and with the nose on the way down, I counted about 5-8 seconds which simulated the situation I was in everytime I dead sticked, I could see bubbles in the fuel lines and the engine would die. Now a recap on the tank and lines situation everything is new. New Hays 11 oz tank, new heavy duty orange pressure line, new clear standard fule line from tank to needle valve and carberator. This is the second time in the last few days the fuel lines and tank have been replaced. I am real sure it's not a hole in the lines or tank. I
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RE: Twist and evolution 46 dead sticking after 2-4 mins into flight.
I have an Evolution .45 that is doing the exact same thing but I get about 8 minutes in to my flight when it does this. I get the bubbles in fuel line, etc. I replaced the fuel system like you did and the results were the same. It runs great for the first 1/2 or 2/3 rds the tank, I can fly inverted all I want with no problems.
Mine always dies during inverted flight too, it is fine flying straight and level. The clunk is fine too. Have you tried tuning with only 1/4 tank of fuel. I am going to try that today and see what happens.
You are not alone. If I come up with an answer to this problem I will let you know.
Mine always dies during inverted flight too, it is fine flying straight and level. The clunk is fine too. Have you tried tuning with only 1/4 tank of fuel. I am going to try that today and see what happens.
You are not alone. If I come up with an answer to this problem I will let you know.
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RE: Twist and evolution 46 dead sticking after 2-4 mins into flight.
I am not an expert at all, but I had one of my O.S.46FX doing about the same thing. Long story short I had to adjust my tank height, in my case I had to raise the tank about 1/8" or so, and from then on it runs great thru the whole tank.
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RE: Twist and evolution 46 dead sticking after 2-4 mins into flight.
Hi lrglnman
My guess is that the clunk pickup is the problem. I used to cut my inside tank line as long as possible yet not let the clunk touch the back inside tank wall. I found out that sometimes the clunk did touch. Now I aim to be about 1/4 to 1/2 inch short from touching, on a tank like you are using. Make sure the fuel line inside the tank is limber enough to move UP and DOWN. Also, do what you can to reduce vibration getting to the fuel tank. The foam rubber around the tank must not be compressed a great deal.
My guess is that the clunk pickup is the problem. I used to cut my inside tank line as long as possible yet not let the clunk touch the back inside tank wall. I found out that sometimes the clunk did touch. Now I aim to be about 1/4 to 1/2 inch short from touching, on a tank like you are using. Make sure the fuel line inside the tank is limber enough to move UP and DOWN. Also, do what you can to reduce vibration getting to the fuel tank. The foam rubber around the tank must not be compressed a great deal.
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RE: Twist and evolution 46 dead sticking after 2-4 mins into flight.
A simple technique to prevent fuel starvation on a down line is to lengthen the fuel intake line between the carb and the tank. Make a loop in the line if you want. The longer line will provide the additional time you need to complete the downline without dead sticking. You might have to adjust the tuning slightly, but you shouldn't notice any significant performance hit. A couple inches is all you need, since the engine should be at idle during the downline anyway.
Brad
Brad
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RE: Twist and evolution 46 dead sticking after 2-4 mins into flight.
Ok has anyone who has had this prob removed the baffel from the muffler. I have thinking I would gain a performance boost. When you remove the baffel you are reducing tank pressure so you have to run the motor rich to get top performance. So when the plane is upside down and in the beginning sage of a long down line , the fuel is moving fast in the line so it runs out before the loop is completed. I think I will reinstall the baffel and see if this helps.
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RE: Twist and evolution 46 dead sticking after 2-4 mins into flight.
You want to ran a three line fuel tank, Two clunks, one goes to the carb, one to the muffler vent nipple. and the last to a fuel dot. You will never run out of fuel.
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RE: Twist and evolution 46 dead sticking after 2-4 mins into flight.
I don't understand? two clunks? do you have the main clunk and the filler tube hooked together?and why do I need a fuel dot? can you explane better? thanks