Sweet smell of the fox 35 stunt

[DanielGelinas]

Well, after 33 years away from the hobby, i just started breaking-in my 60th anniversary fox hemi.  So far so good!

The sweet smell of burning fuel and the whine of the engine without muffler bring back fond memories.

This is my first fox .35 stunt. I recall a friend had one 35 years ago and kept cursing at it during break-in. Finally worked out great for him after the break-in. I personally had a .19 fox and a McCoy .40 at the time. Always wanted to have the fox .35.

This engine will be the perfect engine for my S-1 Ringmaster!

-Danny

[Dennis Holler]

That's Awesome Glad you've come back.  I did the same, built a Ringmaster and hung a Fox .35 on it. Flew it a little at the end of the season.  It and I need a few  things worked out but I can't wait to fly this year.  It was my first flight since about 1984-5.  Great stuff!

[Dalton Hammett]

It's a great sport.....  I came back about 10 years ago after about a 25 year break.  Had an old Ringmaster and a Fox .29 hanging in the basement.   It's been a blast !!!!

Dalton H.

[DanielGelinas]

Have any of you run the fox on muffler pressure during break-in?

Seems the motor vibrates so much on mount that there is constantly air bubbles in the fuel line. 
 Do you think muffler pressure will fix this or should I look somewhere else?

I'm using a 2 ounce perfect profile fuel tank.

Thanks

[Dennis Holler]

I don't know enough to answer that, although I think I have read comments of Fox .35's vibrating.  I am running a Fox muffler on mine the way it came when I dad bought it in the 70's..I'll pay more attention the next time I run it.

[Chris Edinger]

Daniel..

the question here is ... what kind of fuel are you using.... foxes like lots of castor oil... have you added any oil of any kind to your fuel.... what is the mixture of nitro to oil???   check your plug ... it could be causing the rough running.. use a long fox .....we always use... 10% nitro and 26 to 28% castor oil in our foxes..... but once i used to heavy of an oil mixture in a ringed engine.. it vibrated so much it broke a bolt... and yes.. you want to run it kinda  rich at first.. but you could also have it tooo rich and causing the plug to load up and cause vibration, personally I dont think the muffler pressure will change much.. be sure your prop is balenced...

[Chris Edinger]

to kinda let youi know how I found out... I to am a ... returning modeler after 30 some years... I have a fox 35 I bought back in the 70's...... not remembering  what the fuel mixture was... (I always used Fox Fuel)... i bought a  gal of fuel... turns out it was 10%nitro, and 11% Castor and 11% synthetic.... so... I saw some break in oil additive at the hobby shop... bought it and put in the fuel i had... the fox didnt vibrate to bad.. but one could tell it was kinda laboring... and running hotter than I remember...was only using 2 oz of fuel each time.. so then I called my friend Jim Lee.. he set me straight... NO..synthetic... castor only and at the 26-28 % level for a fox... so I found some Sig fuel in that ratio and fired up the  fox again.... man.. what a difference... totally different running engine...
while i was breaking in the fox I also had a new ST46 from the 70's and was also using he same earlier mix i had bought withe the breakin oil added.... ran so rough it was terrrible and the vribration broke a bolt.. changed the fuel for it.. to the original 10% nitro, and 18 to20% oil blend... and again.... wow.. what a difference... Randy smith has a post here about fuels and their effects on different engines... might look that up and read it...

[Chris Edinger]

I found the post randy did... it is in the engine set up forum here on stunthanger and is titled..engine, glow plug tips.... third item on that forum... great article for those of us who have forgotten about how to make engines run properly...

[DanielGelinas]

Thanks Chris,

I doubt its the fuel. I am running brodaks 10% nitro, 29% castor.
The muffler pressure seems to help with the air bubles in the line.
Is it "normal" to see air bubles coming from the tank and goint to the engine? I assume not!

-Danny

[Chris Edinger]

Danny.. no not usually... but vibration caused most of it...you will get some... what kind of tank are you useing on the test stand?/

[Dan McEntee]

   Make sure you don't have too much prop on it while bench running it.  Find an old 10-5 and cut it down to 9 inches and balance it. Use that for your bench break in.You want a normal load on any engine when breaking in, but that's hard to do on a bench mount. Just want somethinmg to grab and start it with, and provide some weight to swing. These old school engines like Foxes and McCoys and the ringed ST engines were designed around the excess castor and need the oil to help carry heat out as well as lubricate. The parts on these engines really are rubbing together until they fit. Modern engines are a different matter and take different techniques, and sometimes no real break in at all!
  I don't currently have a Fox .35 in anything, and I have to remedy that situation. I think they are misunderstood by a lot of guys and a really are part of C/L modeling history.
   Type at you later,
   Dan McEntee
  Florissant, MO

[John Cralley]

I have seen somewhere that adding a few drops of Armor-All to a gallon of fuel will work wonders for stopping fuel foaming. I have never tried it but maybe others who have will chime in here.

John

[DanielGelinas]

Hi Guys,

I'm running a 10-4 prop for the break-in. The tank is a 2 once wedge siting on some rubber foam to minimise vibration.
 
Thanks,

-d

[Jim Kraft]

I use a few drops or a small pritz of Armorall in my fuel. It really helps keep the foaming to a minimum.