kingtoyota

Iam new here, so go easy on me!
My son and Iare putting together a plane with a fox 60 nitro engine. The engine was siezed from sitting for years. We got it freed up with penetrating oil and it has good compression. We are having 2 problems with fuel, first we can't get fuel to flow from the tank to the carb. The vent is hooked up to the muffler port. If you blow into the hose at the muffler, fuel will flow out of the other hose to the carb. It will not pressurize the tank with muffler pressure. The tank does not have any leaks and it holds pressure, no kinked hoses either.

The other problem is the carb. Itook it all apart and cleaned it out good. Iam not sure how to set it up. It has 2 jets, 1 on each side. Iunderstand that this is an old setup, but Iwould like to see if we can make it work.

The engine will fire for a second with a small spray of carb cleaner in it.

Any help is appreciated.

Carlos G

Hi Kingtoyota,

As far as the muffler pressure goes the engine has to be running to pressurize the fuel tank. Fuel tank position relative to the carburetor is important. The needle valve of the engine should be slightly above the center line of the fuel tank as viewed from the side. ( 1/8 to 3/16" roughly) Too low would make it hard for the carburetor to pull fuel into it and too high would tend to siphon or flood the engine. With the carburetor at full throttle and the throat blocked with your finger you should be able to "pull" fuel from the tank through the fuel hose into the carburetor by turning the prop with your hand (make sure the glow plug is NOT connected ) If no fuel will flow then you may have a gummed up needle valve or a loose carburetor that leaks air.

It would be very helpful if you could post a picture or two of the engine so tha we can see what version of carburetor/ engine you are dealing with. Some of the fox engines had some odd design carburetors and had their own method of setting them up.

Hope this helps and good luck.

Carlos G.

w8ye

My Feedback: (16)

The needle valve on the side of the carburetter that the fuel inlet is on is the high speed needle

The other side is the low speed. But send us a good picture of the carb so we can tell if it is a air bleed type carb or not

Rodney

All the old Fox's were run with Castor oil which is what probably made the engine seize up. The easy way to clear that (and also minimize the residual coating inside the engine) would be to heat it up with a heat gun while trying to turn it over by hand. You might find that the little nipple on the muffler is plugged with congealed oil also, just push a common pin or small wire thru it to clear the blockage. Most (if not all) these old Fox's run very well but do like a castor based fuel of about 20 to 22% oil.

kingtoyota

Thanks for the replies. Here are some pictures of the engine. Idid not know about priming the engine with a finger over the carb. Iwill try that today.

Carlos G

Hi KingT,

Thanks for the pictures. W8ye nailed it about the needle valves. It also appears that the bolt behind the cylinder that holds the muffler on is missing if you havent noticed that already. Keep us posted and be careful.

Carlos G.

kingtoyota

Yea, Iknow that bolt is missing. Part of the muffler that the bolt would thread into is broken off. The gasket looks ok, and Iused a little bit of form a gasket when Iput the muffler on.

From what Iread, Ineed to adjust the low speed neddle first, then the high speed. Ithink the low speed feeds fuel all the time, and the hig speed adds to it. Does this sound right?

w8ye

My Feedback: (16)

The usual practice is to open both needles up,

run the engine full throttle and adjust the high speed needle

Then start trying to get the low speed needle peaked out. At some point the engine will get to where it will not accelerate from idle. At this time you open the low speed needle enough to get good transition to high speed from idle. Move the low speed needle little small amounts each time and give the engine enough time to adjust to the new setting before advancing the throttle.

JohnBuckner

My Feedback: (1)

This is certain to cause running problems expecially if you ever get it to the point of flight were it will be operating at full throttle. It will loosen the one bolt and cause a loss of muffler pressure leading to constant flame outs in flight.

For any chance of success you will need to replace the muffler with either an aftermarket strapon or a new muffler from Fox which is still in business.

John

Steve Percifield

My Feedback: (14)

Kingtoyota,

Your posts indicate you are a very new, new comer. Be very careful with this engine. It can inflict serious damage to your fingers and hand. I had one of these many years ago, and it is not a user friendly engine. And that APC prop on the front is a meat slicer. 2 things, as already mentioned, do not operate this engine with the muffler the way it is. It could come off, get into the prop and hurt some one. And secondly, find a club and ask help from some one who knows how to operate glow engines. You will also need flight training.

http://www.foxmanufacturing.com/

this is the link to the engine manufacture. Contact thrm for the mufler replacement and help with carb

JMO

steve

dant-RCU

My Feedback: (3)

Kingtoyota,

I have run Fox engines for 25 years and once broken in and setup they run fine for me.

Your engine has the Mark X carb (just for reference). If your carb is not passing fuel AND you have the high speed needle
open (say 4 turns) then I would say your carb is gunked up also. It is on the outside also. Here is what I would do.

Take the carb off the engine. Remove BOTH needles and soak the carb and needles in laquer thinner or, if you don't have
any, clean fuel overnight. You might want to move the throttle a little while it is soaking. After it has soaked blow out the
needle openings with compressed air (if possible) or use canned "computer dust off" or just really strong breath. Replace
the needles and open EACH needle 4 turns. Put a piece of fuel tube on the inlet and open the throttle full. You should be able
to blow thru the tubing. If you can't then your carb is still gunked up inside. Put the carb back on the engine and try to start again.
You should be pulling fuel. Once you get the engine running and it will be rich so lean out the high speed needle maybe 1/2 turn.
If you have to leave the igniter connected fine. Then set the LOW speed needle and you want it on the lean side if anything.
Once you have the low speed needle set THEN set the high speed needle. You want the high speed needle a tad rich (one or two
clicks rich from max rpm) Once that is set you might want to re-tweak the
low speed needle a tad but do not go rich with it. Contrary to what some might say it is NOT an idle needle, it is low speed
needle and actually meters fuel into the mid-range area.

Three things to remember here:

Duke Fox tinkered a lot and he had his very own ideas on carburation so always remember that.

Two , the Mark X carb needle threads are pretty coarse and a small adjustment will make a big
difference. Most carbs use a much finer thread.

Three, your engine will run much better with an idle bar glowplug. Especially in the attitude you have it installed. I am currently
running a Fox .46 in that config and it will not run well unless I use an idle bar glow plug. I had the same scenario with an older
Fox .78 and a newer Fox .74.

The previous advice on fuel is good. You must run some castor. Omega pink is fine and I use it but add 3-4 oz of castor except for the .46
which runs fine on straight Omega pink. I have never run more than 10 percent nitro in any of my Fox engines EXCEPT the .46 and it
runs fine on 15% , but my normal 2 cycle fuel is 10% anyway so that is what I currently am running.

My .05 here. There is a ton of advice in these forums - you just have to dig. Club Fox has a lot of info also.

Dan

kingtoyota

Thanks for the info. Ihave the carb soaking now. Idid clean it out before. It was siezed up. I had to heat it up to get the throttle to move at all. Isparyed out the ports and blew compressed air thru them. Iwas looking at the carb closer, and it looks like the big needle valve(on top in the picture) controls the main inlet of fuel from the tank, and the small (bottom in picture) valve moves out to open up when the throttle is opened. Does that make the top one the low speed valve and the bottom one the high speed valve? Iassumed that the smaller one was the low and the bigger was high.
Thanks.

Carlos G

Hi King,

The top larger needle valve is the high speed and the smaller lower needle valve is the low speed (idle). Be careful...

Carlos G

50+AirYears

Just a quick blurb about initial settings for the Mark X carb from an old Dukes Mixture column. For the 60 through 78 carb, the initial low speed needle setting is to turn the needle out from the friction clip, turn it in till it just engages the clip, then turn in another 2 turns. For the high speed, back the high speed needle out of the clip, turn in to the point of engagement, then turn in another 5 turns.

There was a version of the Fox carb just before the current MK X, a twin needle design, where the proper setting procedure was to set the high side slightly rich, throttle down, adjust the low speed needle and idle, THEN set the high speed, just the opposite of anybody else's carb. Drove a lot of engine people nuts, trying to get decent runs out of these engines, Even P. G. F. Chinn made a comment about this carb in his MAN column.

At one point, Fox 60s were very high compression to operate on low or no nitro fuels during a period of nitro shortage. A couple different engine columnists have remarked on various Fox .60s ability to turn larger props. I believe RC Reports rated the Fox Eagle 3 turning 1.20 sized props at RPMs equal to the high end 4 strokes.

I've also found because of the course needle valve thread, sometimes it's a good idea to slip small lengths of fuel line over the needles to kind of form a gasket to cut down on air leakage. This hasn't been unique to Fox.

WhiteRook

My Feedback: (38)

interesting stuff

kingtoyota

I got fuel up and got it running now. I had to soak the carb good to clean it out some more. Now all I have to do is get the mixture set right! Thanks for all the advice.

kingtoyota

Got it running good now. Had to play around with both needle valves and I got it. Does anyone know about flying a citabria115 plane? That is what this fox60 engine is in. The wingspan is about 5.5feet. I am wondering how good of a starter plane this will be.

w8ye

My Feedback: (16)

Better find someone experienced enough to fly it first?

jaka

Hi!
Not a good starter plane, and not a good newbie engine! Get a trainer plane instead, like the Kyosho Calmato and a modern, reliable .40 engine!
That old FOX .60 "Eagle" must sound terrible with that small silencer!

Rodney

Properly set up and trimmed, your plane should work well as a trainer. The old Fox Eagle was powerhouse for it's size and was used by many a first time flyer with great success. The biggest complaint most had was that the carburetor was a bit different from the standard of it's day and those who refused to read and heed instructions often had a problem with it. For others it was a very dependable and long lasting engine. They do like a fuel with castor oil and about 20 to 22% oil.