high end needle security
09-28-2009 | 06:31 AM
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From: Nottingham,
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high end needle security
Hey, what do "Ya'll" do to ensure that the high end needle screw doesn't move during flight. My Tucano has a fox 45BB engine and even with the security clip on the high end needle screw, it turns extremely easy. I worry that it could turn during flight. I think I read somewhere on the forums that some use small wire ties once they have them set. Wire ties for me are not an option due to the cowl.
09-28-2009 | 07:12 AM
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From: Nottingham,
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RE: high end needle security
ORIGINAL: Insanemoondoggie
Heres what I do ,I use large fuel line, see pic .
Heres what I do ,I use large fuel line, see pic .
09-28-2009 | 07:20 AM
#4
RE: high end needle security
Insanemoondoggie's fix is viable and I do the same thing but keep in mind what keeps a normal needle tightly in place. It's not the threads and it's only partially done by that little metal clip. That thing is to give to a physical feel (clicks) when you adjust the needle. There is a rubber O-ring on the needle. If it gets worn you can have engine running difficulty in the near future as air gets sucked in of fuel gets blown out of it.
09-28-2009 | 07:31 AM
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RE: high end needle security
ORIGINAL: Mr67Stang
Insanemoondoggie's fix is viable and I do the same thing but keep in mind what keeps a normal needle tightly in place. It's not the threads and it's only partially done by that little metal clip. That thing is to give to a physical feel (clicks) when you adjust the needle. There is a rubber O-ring on the needle. If it gets worn you can have engine running difficulty in the near future as air gets sucked in of fuel gets blown out of it.
Insanemoondoggie's fix is viable and I do the same thing but keep in mind what keeps a normal needle tightly in place. It's not the threads and it's only partially done by that little metal clip. That thing is to give to a physical feel (clicks) when you adjust the needle. There is a rubber O-ring on the needle. If it gets worn you can have engine running difficulty in the near future as air gets sucked in of fuel gets blown out of it.
09-28-2009 | 11:38 AM
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From: Poolesville, MD
RE: high end needle security
Often I "FIX" people's engines that are having problems, by using a bit of exhaust tubing ( much like Insanemoondoggie ) or at worst I'll put a wire tie around the clip just tight enough to provide a bit more friction to the detents.
09-28-2009 | 11:56 AM
#7
RE: high end needle security
ORIGINAL: billd76
There are two ''lock'' clips on the needle. The clips work well until you get about 2 turns out, then the detents on the clips start to become un-effective, the detents that set in the grooves do not run the entire length of the clip. Poor design in my opinion.
There are two ''lock'' clips on the needle. The clips work well until you get about 2 turns out, then the detents on the clips start to become un-effective, the detents that set in the grooves do not run the entire length of the clip. Poor design in my opinion.
1) Replacing the O-ring.
2) Bending the clips to the center in order to obtain more spring effect.
3) Placing one or two o-rings in the groove of the needle (see attached schematic), in order to get some friction on the clips when they slide over that point. A piece of fuel tube may work as well. Note that the exterior diameter of this insert should not be so big as to prevent the spring action of the clips while they are over the metal portion.
If the position of the needle is consistent, and the clips are frequently on the groove, I would go for a more radical solution: sliding the needle inside the knob enough as to locate the clips at the right spot after normal tuning. The knob holds the needled by interference only; hence, it can be made slide cold or hot, which is even easier (see attached schematic).
09-28-2009 | 01:35 PM
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From: Nottingham,
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RE: high end needle security
ORIGINAL: lnewqban
I suggest pulling the needle valve completely out, then:
1) Replacing the O-ring.
2) Bending the clips to the center in order to obtain more spring effect.
3) Placing one or two o-rings in the groove of the needle (see attached schematic), in order to get some friction on the clips when they slide over that point. A piece of fuel tube may work as well. Note that the exterior diameter of this insert should not be so big as to prevent the spring action of the clips while they are over the metal portion.
If the position of the needle is consistent, and the clips are frequently on the groove, I would go for a more radical solution: sliding the needle inside the knob enough as to locate the clips at the right spot after normal tuning. The knob holds the needled by interference only; hence, it can be made slide cold or hot, which is even easier (see attached schematic).
ORIGINAL: billd76
There are two ''lock'' clips on the needle. The clips work well until you get about 2 turns out, then the detents on the clips start to become un-effective, the detents that set in the grooves do not run the entire length of the clip. Poor design in my opinion.
There are two ''lock'' clips on the needle. The clips work well until you get about 2 turns out, then the detents on the clips start to become un-effective, the detents that set in the grooves do not run the entire length of the clip. Poor design in my opinion.
1) Replacing the O-ring.
2) Bending the clips to the center in order to obtain more spring effect.
3) Placing one or two o-rings in the groove of the needle (see attached schematic), in order to get some friction on the clips when they slide over that point. A piece of fuel tube may work as well. Note that the exterior diameter of this insert should not be so big as to prevent the spring action of the clips while they are over the metal portion.
If the position of the needle is consistent, and the clips are frequently on the groove, I would go for a more radical solution: sliding the needle inside the knob enough as to locate the clips at the right spot after normal tuning. The knob holds the needled by interference only; hence, it can be made slide cold or hot, which is even easier (see attached schematic).
