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  • December 17, 2017, 10:15:04 PM

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Author Topic: Does anyone know what NVA Bob Gieskie used in his Fox's?  (Read 605 times)

Online Dennis Toth

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Does anyone know what NVA Bob Gieskie used in his Fox's?
« on: December 05, 2017, 12:43:02 PM »
Working with the NVA on my Fox in my El Diablo, I have a Randy Smith fox NVA. I was wondering if anyone recalls what NVA Bob Gieskie used when he ran the Fox?

Best,    DennisT


Offline Dave_Trible

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #1 on: December 06, 2017, 05:23:27 PM »
Dennis this is one of Bobís own favorite Foxes with a zillion miles.  Box stock Fox .35 needle assembly.

Dave
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Online Brett Buck

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #2 on: December 06, 2017, 05:55:29 PM »
Working with the NVA on my Fox in my El Diablo, I have a Randy Smith fox NVA. I was wondering if anyone recalls what NVA Bob Gieskie used when he ran the Fox?

   The stock (flat wedge) needle works fine, although some of them work better than others, depending on how the flat lines up with the holes when set for flight. One click either way is good for about 15-30 seconds of run time.

    Brett

Offline Matt Spencer

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #3 on: December 06, 2017, 06:25:43 PM »
Wood Screws .  S?P  ( Just Kidding ) .

Offline Dave_Trible

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #4 on: December 07, 2017, 04:30:16 AM »
Wood Screws .  S?P  ( Just Kidding ) .
You are very observant.  Yes Bob used wood screws on the Foxís.  Thatís one of the giveaways about the engine- like an autograph.

Dave
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Online Dennis Toth

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #5 on: December 07, 2017, 05:01:54 PM »
Guys,
The reason for the question is that I'm having a runaway issue with my Fox 35 in my El D. I have a Randy Smith PA-fox NVA, uniflow tank, 7%N/ 27% oil (50/50), Fox muffler, Sig RC plug, 9x6 APC prop. Issue is that it starts a little rich then as it warms on the ground breaks into a screaming 2 cycle. All efforts to richen have no effect. I had the needle out 5 turns from where it ran rich at the start and made no difference. I tried muffler pressure and still the same (one flight it went way rich but after that just kept screaming). I tried open vent, no change.

This motor has the bypass partially filled with JB Weld (in place of the stick). Could the JB Weld be adding to the heat causing the runaway? Could going to a colder plug (like an Enya 4 or 6) claim it down?

Best,   DennisT
« Last Edit: December 07, 2017, 05:48:33 PM by Dennis Toth »

Offline Russell Shaffer

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #6 on: December 07, 2017, 05:47:08 PM »
I once had a piece of translucent plastic get into a fuel line.  It would randomly get against the filter inlet.  I found it when I took EVERYTHING apart.  It was impossible to see through the fuel line.
Russell Shaffer
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Just North of the California border

Online Brett Buck

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #7 on: December 07, 2017, 06:13:02 PM »
This motor has the bypass partially filled with JB Weld (in place of the stick). Could the JB Weld be adding to the heat causing the runaway? Could going to a colder plug (like an Enya 4 or 6) claim it down?

   There could be a leak or improperly-torqued head screws (they need to be *very even* on the Fox), but this is also the classic symptom of a worn-out piston/cylinder assembly. Particularly so if it worked OK before and now it doesn't.

      Brett

Online Dan McEntee

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #8 on: December 07, 2017, 08:22:54 PM »
     If five turns of the needle have no effect then there is an air leak of some kind. I have seen glow plugs still work but leak air as the engine heats up. As bret mentions, all the bolts need to be evenly torqued on a Fox.35. When I get a Fox.35 that is new or new to me, one of the things I always do is chase all of the holes with a good 4-40 tap. You would be amazed at the metal that you can get out of one of these things some times. I really leaky needle thread is also a problem. I use the fuel line trick on the needle threads to help seal them up if I'm using a stock needle valve assembly. If this is the same engine you mentioned in another thread where you were running 7 inch pitch props, that may have done the piston and liner in.
  Type at you later,
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Offline john e. holliday

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #9 on: December 08, 2017, 11:01:42 AM »
I was going to say Fox .35 Stunts like 10-6 Top Flite wood props.   But that was only on one of my Fox's.   The rest of them I'm using 9-6 or 10-5 composite props. D>K

Yes check for leaks in the whole fuel system.   I have nylon washers on some of my needle valve spray bars as well as fuel line on the needle.   Used Teflon tape at one time also.  Silicon tubing is another part that will give fits so mine gets replaced every time the engine starts acting up. 
I was always taught to respect my elders, but it keeps getting harder to find one.
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Offline RandySmith

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #10 on: December 08, 2017, 11:12:25 AM »
Many many things  can cause  this, check ALL of your fuel components, I have seen this exact thing  caused  by a  castor slag...  that is a clear  thick piece of  "flecked castor that has become semi solid"  that is  more common than people think, and it happens more often in  cooler  weather, but can happen  all year around

Randy

Offline Matt Spencer

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #11 on: December 08, 2017, 09:07:59 PM »
The 59 did that , after a ' vertical landing 'from a wingover with a high tailwind quotiant .

Cracked Case under one lug ,didnt spot it tillit'd fretteda bit . :(

Online Al Ferraro

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Re: Does anyone know what NVA Bob Gieskie used in his Fox's?
« Reply #12 on: December 09, 2017, 06:51:45 PM »
[quote author=Dennis Toth
    All efforts to richen have no effect. I had the needle out 5 turns from where it ran rich at the start and made no difference.

Best,   DennisT

  Sounds like you have dirt. Take the  needle all the way out and flush the spray bar with fuel, use a filter or clean the filter if your using one, and flush the tank. When you open the needle past 5 turns the engine should run really rich, if not you got other problems like tank, leaky back plate ect.
Al


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