Author Topic: Fox 35 Loose Needle Valve? (Read 1081 times)

Warren Leadbeatter · « **on:** February 26, 2007, 06:12:44 PM »

Hi all,

While flying my Nobler today I noticed that my Fox 35 (50th Ann. edition) needle valve has a bit of side to side free play. Is this normal? The little stopper thingy stops it from turning, but I'm guessing it could vibrate from side to side affecting the tune of the engine.

See pic attached. Also attached is a pic of my new Stooge that I made on Sunday.

Cheers

James Lee · « **Reply #1 on:** February 26, 2007, 06:16:40 PM »

Warren
That side to side motion is not uncommon with the usual Fox QC.... It does tend to make an air leak which is not good.... Typically a piece of silicone fuel line over the needle just slightly longer than the distance between the wheel on the needle and the nva body will make a decent air seal. Maybe not great but it will work.

FWIW
Jim

Paul Taylor · « **Reply #2 on:** February 26, 2007, 06:23:21 PM »

I think most replace the Fox NVA with a ST type.

I like the stooge and the plane, but I really like the green grass. Still winter here and all the grass is brown. $:-\$

Bob Reeves · « **Reply #3 on:** February 26, 2007, 06:23:42 PM »

As Jim said, not unusual at all, even have fuel tubing on the OS needle in my Saito 40 with UHP manafold.

Jim Thomerson · « **Reply #4 on:** February 26, 2007, 06:44:48 PM »

I put one of my 1970's Fox stunt 35's back together with the plan of using it in an OTS airplane. I ran it on the bench with a Fox NVA. It now has an ST NVA.

Marvin Denny · « **Reply #5 on:** February 26, 2007, 08:21:48 PM »

I took some of my stunt 35 needles to a plating establishment, and had him plate about 0.003 inch per side of silver on them and it cured all the side to side play.
Marvin Denny

Shawn Kuntz · « **Reply #6 on:** February 27, 2007, 07:55:35 AM »

ST Needle Valve Assembly? Is this Super Tigre? Where do I get one?

Bill Little · « **Reply #7 on:** February 27, 2007, 08:04:31 AM »

I have always found the "little chunk of fuel tubing" to be a great help with the Fox 35 Needles.

Less than a 1/4" piece on the needle and thread it in. Seals the assembly real nicely!

Bill <><

Warren Leadbeatter · « **Reply #8 on:** February 27, 2007, 08:16:08 AM »

Shaun,

You can get genuine ST NVAs on eBay from time to time for around $20 but you can also get after market ones from Leonard Neumann at http://www.clstunt.com/products.htm for about $12

Bill,

I have already put a small piece of tube (about 1/4" long) seems to work fine. Much more consistent running now. I think I may have also had a pin hole in my home made tank. Fixed now.. will see how it goes tomorrow, weather permitting...

Cheers

L0U CRANE · « **Reply #9 on:** February 27, 2007, 01:12:06 PM »

Warren,

The piece of fuel tubing seals between the inner knob and the spraybar, of course. It also puts some tension on the threads IN the NVA, which aids seal and somewhat further snubs vibration.

Aside to Jim Thomerson: I find the ST spraybars a bit large diameter for my liking. OS and ENYA CL NVAs are available, and both are between the ST and the Fox spraybar diameter.

...Ah, but then, at my home altitude of ~5000', I need a bit more airflow over the spraybar, don't I?

RandySmith · « **Reply #10 on:** February 27, 2007, 02:10:28 PM »

Quote from: Warren Leadbeatter on February 27, 2007, 08:16:08 AM

Shaun,

You can get genuine ST NVAs on eBay from time to time for around $20 but you can also get after market ones from Leonard Neumann at http://www.clstunt.com/products.htm for about $12

Bill,

I have already put a small piece of tube (about 1/4" long) seems to work fine. Much more consistent running now. I think I may have also had a pin hole in my home made tank. Fixed now.. will see how it goes tomorrow, weather permitting...

Cheers

HI

You can also get ST NVA from Aero Products, and the better PA NVAs the Stainless steel ones that are made to fit the FOX 35 require NO grinding, sealing , washers or filing the sides flat. just bolt them in and they work

Randy

Bill Little · « **Reply #11 on:** February 28, 2007, 10:58:33 AM »

I have several PA NVA for the Fox 35. The spray bar looks just like the Fox one, except it is stainless steel. It has a collet to lock the needle "similar" to the ST style, but this one has a *nylon* (

) insert that seals the needle completely. It also means that the collet only needs to be finger tight.

This NVA is definitelty the best of both worlds with out a doubt.

Bill <><

Terry Bolin · « **Reply #12 on:** February 28, 2007, 12:12:16 PM »

I was running a NEW Fox 35 on the test stand last night to break it in and not have to clean a airplane up afterwards. During the first run I noticed the engine RPM Was inconsistent but then I realized that I forgot to install the short Silicone piece on the needle valve. I have done this since the 70's and it really works well plus, helps hold your adjustment. That fixed me right up last night. Try that before you spend the money for a ST NVA.
Good Luck!
Terry B.

Tom Perry · « **Reply #13 on:** February 28, 2007, 05:09:05 PM »

Has anyone else tried the teflon tape sold for plumbing to solve this problem? Streched very tight it effectively seals any air leaks and keeps any side to side play to a minimum.

Author Topic: Fox 35 Loose Needle Valve? (Read 1081 times)

Warren Leadbeatter

Fox 35 Loose Needle Valve?

James Lee

Re: Fox 35 Loose Needle Valve?

Paul Taylor

Re: Fox 35 Loose Needle Valve?

Bob Reeves

Re: Fox 35 Loose Needle Valve?

Jim Thomerson

Re: Fox 35 Loose Needle Valve?

Marvin Denny

Re: Fox 35 Loose Needle Valve?

Shawn Kuntz

Re: Fox 35 Loose Needle Valve?

Bill Little

Re: Fox 35 Loose Needle Valve?

Warren Leadbeatter

Re: Fox 35 Loose Needle Valve?

L0U CRANE

Re: Fox 35 Loose Needle Valve?

RandySmith

Re: Fox 35 Loose Needle Valve?

Bill Little

Re: Fox 35 Loose Needle Valve?

Terry Bolin

Re: Fox 35 Loose Needle Valve?

Tom Perry

Re: Fox 35 Loose Needle Valve?