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Jett 56lx

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Old 05-01-2011, 04:24 PM
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cmmicroheli
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Default Jett 56lx

Ihave a Jett 56lx that seems to be leaning out after about two minutes of flying. I'm running a 9x7 zinger my needles are set as follows mid range is half a turn in from flush and high speed is four and a half out. Motor seems to come and go as it runs well some times and other times it does not. I have also pressure checked the tank and itsfine. Any help would be appreciated.
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Old 05-01-2011, 06:04 PM
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Default RE: Jett 56lx

Hi !

First, needle positions you noted are "about" right, but the only way those are correct is when the engine runs its best. The low/mid mixture is factory set - should not be adjusted until after the engine has run for a while - and in that case turn it no more than 1/4 turn either direction.

Usually when the engine runs erratic or inconsistant, you are dealing with a fuel system problem. With the energy these engines put out, a lot is transmitted to the airframe, and with that, you get a huge risk of fuel foam (even if you do not see it it will happen in flight)

First step - make sure the fuel tank is not touching ANY structure. Foam padding all the way around it. There is no way around this absolute must.

Second - high speed needle setting - find ground peak rpm (briefly), back off from that 800-1000 rpm for flight. When the engine unloads in flight, it needs the fuel.

Which aircraft is the engine installed in? What prop are you using ?

If possible post a few photos of the engine installation and the fuel tank install. That will help me a bunch here.

Bob
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Old 05-01-2011, 06:40 PM
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Default RE: Jett 56lx

Hey Bob. I'm running this in a sundowner 50 and I'm using a zinger 9x7 prop. The tank is completely wrapped in foam I did have one spot of interference at the top of the fuselage but Iwas able to remedy this. I will get some pics posted tomorrow. Thanks
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Old 05-01-2011, 07:28 PM
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Default RE: Jett 56lx

Fatten that puppy up and give it the fuel as well as a steeper prop.
I know what you are trying to do.
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Old 05-02-2011, 03:12 AM
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Default RE: Jett 56lx

Hey vic If this thing gets any richer on the ground Idont see how it would ever fly. Idont get it. I think Ipicked up a female. Some days it runs awsome and others its a dog. Idid find a leak on the rnv and seems to be a pretty good one It was leaking at the packing nut and needle.for the moment i have a piece of fuel tubing over it to seal it up.if it worksI will order some parts to fix it.That may be all the problem right there. I wont find out till later this week though.
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Old 05-02-2011, 10:26 AM
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Default RE: Jett 56lx

Tighten the packing nut. You should have it snug so you need a bit of effort to move the needle. If it is leaking it is way too lose.
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Old 05-02-2011, 02:03 PM
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Default RE: Jett 56lx

Packing nut is as tight as Iwant to tighten it. The leak seems to be coming up where the needle passes through the nut.
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Old 05-08-2011, 01:14 PM
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Ill be happy to report the needle valve was indeed the problem. I had a chance to sneak in a few flights this morning and with the fuel line over the needle where Ifound the leak, the motor ran like it did beforewhich is screaming. Thanks for the help.
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Old 05-16-2011, 01:30 PM
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Default RE: Jett 56lx

Great to hear.

Possible the insert inside of the packing nut got cross threaded. Rare but it can happen sometimes.

If you can, send me a photo or three of the aircraft and the engine installation

Bob
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Old 05-25-2011, 05:24 AM
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Default RE: Jett 56lx

I think my 56 Jett is coming today. Can't wait to see this beauty.
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