mustang madness

if anybody out there can help me?. I have a p-51D mustang w/a os 46-fx. my problem is that i have the engine mounted horizontal and when the cowl is installed the needle valve is about 3/4 of an inch below the surface .What can i use to extend the needle valve to make it more accesseble.Thanks for the help.

JimTrainor

The needle valve has a small hole and set screw into which you can insert a length of piano wire.

You can also rotate the back plate to change the position of the needle valve if that helps. The extra length of tubing from the carb to the needle valve won't affect anything.

ShempHoward

My Feedback: (3)

Sorry - You CANNOT rotate the back plate on any 46FX I have ever owned or have seen. Check the backplate carefully for the flat spot on top.

The other suggestion about using a short piece of piano wire in the end of the needle valve and keeping it in place via the tiny set screw works well but use some blue locktite when doing so.

JimTrainor

oopss.... I had mine off the other day and it crossed my mind at that time that I could do it, but didn't actually try! Silly me.

canadianjosh

The piano wire idea is the only way to extend it, be sure to try and file a small flat spot in ti though and really tighten the set screw because this thing has a tendency to loosen.

Damnathius

There is also the cable extension with a 1/16th wheel collar on the end for adjustment. Any of the heavier pushrod cables will work for the extension. This also helps with any misalignment on the exit hole.

Razor-RCU

My Feedback: (50)

Use the hole in the end of the needle valve but try a small allen wrench (1/16th?) it looks better, grabs better, and is easier to adjust!

Azcat59

There is another way to skin this cat with nice cosmetic results. Get a #2 Allen head sheet metal screw (DuBro sells them), the short 3/8" length is best, and grind the threads down a little with your Dremel. Then stick it in the hole where you would put the music wire, and tighten the set screw on it. Now, through a small access hole in your cowl or fuselage top, you can stick a 2-56 ball driver in and make the adjustments with the engine running. Only a small hole shows. Works great, even on 120 size!

Clair Sieverling

Cyclic Hardover

My Feedback: (3)

Use a "allen wrench or hex key wrench" Just remove the set screw and stick one down in their and cut it to size. Of course you'll have to remove the needle valve every time you remove the cowl but so what.

Flypaper 2

Saw the assembly off the back plate and screw it to the firewall. works for me.

Pepe J

My Feedback: (2)

This technique is similar to the piano wire extension, but I use a short piece of Nyrod and pieces of 2-56 threaded rod.

Thread one end into the Nyrod with enough of the un-threaded piece exposed to be retained in the needle valve by the set screw. Trim to length and with a short piece of full thread 2-56 rod, screw that into the other end of the Nyrod with some thread exposed. Now make up a small "Button" that is drilled and taped for 2-56 thread and glue it on. I made a knurled one out of aluminum.

This method has two advantages. If you should have a crash the Nyrod will shear off and is less likely to cause damage to the needle valve assembly. The other is the Nyrod absorbs vibration and the chance of needle vibrating and adjusting the mixture in flight is less likely.

Happy Fly'n....