Found problem on Hyper Viper

LAST EDITED ON Feb-26-04 AT 07:56 PM (CDT)
 
After having a less than successful first flight with my Cox Hyper Viper, and seeing lap times on 35 foot lines posted here of 3 seconds (mine were 5-6 according to bystanders est.) I desided to have a look at the plane.
What I found was a partly plugged fuel outlet nipple at the fuel tank. Plugged with a clear, silicone like substance.After removing this with a small drill bit, I was able to get fuel to flow out of the tank, but the engine still won't run correctly. Now, it runs a little, coughs, then runs backwards. I think I have some of this stuff in the venturi, I'll check tomorrow. I did get it to run one time for about a minute, but then the needle valve spun itself out and killed the engine. I checked for a spring on the needle valve and it's there, but the valve is very sloppy.
This thing must be possessed!

Addendum:
Called Tower Hobbies this morning to see if I could get some warranty on this plane. Was told to call Cox. When I explained the problem to Cox, they told me I can't get warranty because I fooled with the fuel tank and the plane had been crashed. I told them it crashed because of engine problems during a inside loop. When I pressed them, they said I could send it back to customer no service, but there was nothing they could do. Thanks Cox.

Rob Johnson
Orange,CA.

Now you see why it is C*x not Cox!

Larry and Rob,

I am a modeler. I know lots of modelers.

I wouldn't warranty anything, including a bowling ball, which has been handled by modelers.

Well, well...buckle your seat belts, here we go!

Rob,
I bet you’re correct in thinking that you have a bit of contamination in the engine. At this point you might be better off trying to clean it out yourself.

You’ll probably experience more headaches by trying to deal with C*x on this one.

Good luck.

Hey Dan, I hear ya! I too, am a modeler! God help us.

Don't want to rain on anyones parade, but for the first time that I can recall, the Hyper Viper instruction sheet called for running 3 tanks of fuel though the engine before flying (note my post from today and how I followed those instructions!). That must have been due to Mike Pratt. Another surprising item was the fuel recomendation--they just didn't say to buy Cox fuel--probably also M.P.

I guess the bottom line is that you should run at least a tank's worth of fuel through the engine while mounted on the plane and using the supplied fuel assemby before comitting to the wild blue yonder. So chalk it up to worhtwhile experience and move on (and have fun).

Agreed. Also a good idea to get a sense of whether engine is developing adequate power prior to flying the model.

Makes even more sense, once model is in the air and obviously not performing to some sort of minimum standard, to avoid the temptation to do a loop.

LAST EDITED ON Feb-27-04 AT 11:34 PM (CDT)
 
As stated in another post, I did run the three tanks of fuel for break in. C}> x states to do this to all there planes(PT Trainer, Piper Cub, now HV). I also posted the thing flew like a Piper Cub. I know of two other HV's, belonging to friends of mine, that have no such problem. I run 25% for flight. Ran one tank, slow lap times, but could not resist dropping the hammer. I knew it was to slow.
It's not my fuel or inproper break in. It's debris in the tank.
It's not the end of the world, just thought I'd post what I found out in case someone else had the same kind of problem and could return it BEFORE tinkering with it so C}> x WOULD warrenty it. Also felt there Customer Service could be a little more....less of...an a**.
Now, where did I put that Tee Dee.....I see an engine swap coming ....
Rob Johnson
Orange,CA.

RJ Bob and I were assembling one of his HV's today when he discovered that the overflow tube was cemented so tightly to the top of the tank that he could barely blow air through it while plugging the pickup and blowing into the fill tube.

Maybe there is a bit of a QC problem at Cox, especially with the tanks.

OS

There are two comments I could make in all this.

One is, to check everything to make sure it is OK. If there is a quality control problem in a certain area (tank?) make sure the tank is functioning, not leaking, etc. Even if I bought a metal tank, I would check it before installing it in my plane. Anything can happen to anything.

The second is, and I don't mean to sound harsh, but when you knew the plane was flying too slow and proceed to try the loop, the responsibility was totally yours for any ensuing damage. Whether you build the plane or buy it, if the engine is not running right, do NOT attempt any maneuvers. Run it out of fuel and then determine what the problem is so you can fix it.

Now, if you assemblied the plane properly (an ARF) and ran the engine properly and attempted a loop and the wings folded in the first turn, then I may question the design, etc. But in this case the fact that you attempted the loop without the engine running properly places the responsibility for what follows on your shoulder.

I do appreciate your passing on the problem with the tank. It is good to note this and for others to be aware of a potential problem that may be easily solved before taking it out to the field.

LAST EDITED ON Feb-28-04 AT 04:44 PM (CDT)
 
Yea, I know!
It's hard to resist pulling the trigger when your in the air. The way the engine was running it would have taken quite awhile to run the fuel out.
Watched one fly today that was running 4-4 1/4 second lap times. Looked to be having no problems.
This has served to teach me a lesson. Today while trimming my flapped Akromaster I flew out two tanks of fuel in level flight because things were not "right". What I brought home was a plane in one piece.
Rob Johnson
Orange,Ca.

>This has served to teach me a lesson. Today while trimming
>my flapped Akromaster I flew out two tanks of fuel in level
>flight because things were not "right". What I brought home
>was a plane in one piece.
>Rob Johnson
>Orange,Ca.

Good show! I think we have all gone through it. The engine isn't running right but we will try it anyway. Bad idea. Fly it out. Fix whatever needs fixing (even if it is just a tweak on the needle) and then fly it again.

Rob,

Please contact me,

800-525-7561 x222

Thanks,

Scott Winans