ST needle not the cats meow

[Paul Taylor]

I had a ST needle in my OS 25 in my SkyRay. I could not get a steady needle at 8rodaks. I swapped it out with a standard OS NVA. Bingo it worked. I tried a few times to clear the ST NVA with pressure fuel and air, no luck. Any one else ever have this problem?

[Mark Scarborough]

Recently, At the NW regionals, I had my FP 40 in my Oriental, couldnt get a good setting, my discovery was that the needle was bent. Not sure how it happened, it did go through a splat on another plane but the needle never appeared to have hit the ground. changed the complete valve assembly and all was good again.

[Steve Helmick]

Any type Needle Valve Assembly can cause problems, as you'll no doubt find out, eventually. The ST's/clones typically work fine, or they're obviously broken. The OS can look fine, and not work worth a darn. If the OS spraybar was the normal .156" diameter, I still wouldn't be using them. Try a Randy Smith needle assembly and see what you think...my choice.    Steve

[Ralph Wenzel (d)]

Aha. Then that makes the OS NVA "the cat's pajama's.  You're too young for that one. 

And 23skiddoo to you! (Whatever that was supposed to mean - LOL)

[john e. holliday]

The Brodak 25 has a needle valve assembly like Super Tigre.  On on of the flights I landed inverted in the grass.  The needle was slightly bent.  Had to loosen lock nut to re-adjust.  Two more flights with out getting the needle setting back.  Took time to really check out the system.  Had to put a peice of fuel line on the spray bar between the needle valve nut and the locking nut.  Must have been a slight air leak as the needle setting is back where I like it and was consistant.  Have fun,  DOC Holliday

[Keith Spriggs]

And 23skiddoo to you! (Whatever that was supposed to mean - LOL)

Oh you kid

[Paul Taylor]

I will check it out next week when we get bavk home.

[Leo Mehl]

Needle valveas an assemblies have always been a pain in th you know what. There is only one solution. If it don't work throw it away and get a new one!

[Randy Cuberly]

Paul,
Over a many years period of time I've found several ST spray-bar assemblies that had small pieces of brass jammed into the needle seat.  This causes the kind of symptoms you experienced.  Presumably this happens during the machining process when a burr can break off from the cross drilling process.  This was a topic of discussion many years ago in the stunt community but haven't heard much about it lately.  Sounds like you may have re-discovered it.
Not much fix for it except to replace the entire NV assembly because the needle and seat are usually damaged in this process.

Randy C.

[Bill Little]

Well, I have used a lot of different NVAs.  The only ones I have never had any trouble with are the ones Randy Smith has made up with the nylon (or whatever it is!) collett in the locking cap.  You do not have to tighten the cap over finger tight, no air leaks, and the needle doesn't move unless you want it to.  I generally replace my "good engines" NVA with Randy's.  PLus he has them made in three different size bodies to fit everything,including turned down centers for the Fox 35.

[Randy Powell]

Mark,

>>Not sure how it happened...<<

I can't imagnine.

I like the Randy NVAs also. I use ST jobs sometimes, but mostly Randy Smith type. I've gotten that design from both Randy and from Len Neumann.

[Mark Scarborough]

rANDY,,,   
You would think with all my recent experience with unconventional landings,, (at least by everybody elses standards,, seem to be convention with me ) I would have known, but hey, it didnt touch anything so who woulda thunk!

[Steve Helmick]

Mark...probably bent by inertia. It's a funny thing. Vibration has broken some needles off for me, including a Randy Aero unit. Some day, I may get the broken NV out of that spraybar. Or not.  Steve