This engine is 32 years old and never been run. I started a break in today, but it will not keep running, unless the glow plug is connected to the battery. When I take the glow plug power off, the engine runs for a couple of seconds and quites. Put the glow plug power back on, it start right up and will continue to run until you take the power of the glow plug. I've tried running it throught a full tank of fuel, with glow plug connected, but it still quites when the power is disconnected from the glow plug.
Any ideas??

Put in a new plug. Weak/defective plugs frequently act this way because they can not stay hot.

It was a new glow plug, but I will try a different one tomorrow.
Thanks

fishingnuts, I assume you have tried leaning out the high speed needle? Is this a photo of your engine? Man, that's an old timer. O.S. started making the .35S in 1964.

hey same exact engine I used on my 1st trainer

I still have it.
Here's a pic of it next to my Saito FA-45
We did the remote needle valve conversion back in the 80's
http://www.pontiacs.org/pics/projects/RC/IMG_2565.JPG

I found mine ran best with an idle bar plug when I was flying with it 15 years ago.

I had the same issue with the Saito, it took a little tweaking of the idle screw to get it running off the glow starter. It was way to lean after moving from Washington to up here in Colorado.

I haven't run the .35 up here yet.. I lost the stupid muffler..

If you give up sell me the muffler and strap

The first thing you need is a fuel with 25% all castor as a minimum. The second thing you need is more fuel with 25% all castor . Then you need to run it as rich as it can possibly go for at least the first tank and not too much leaner after that for another few tanks. Let it run in a 4 stroke for maybe 40-60 minutes before leaning it out into a rich 2 stroke. You won't need much, if any, nitro. Don't even try running this on normal RC fuel or it'll have a short life.

It was the glow plug. Been running it on fuel with 10% nitro. It runs excellent at low rpms, but cuts out on high. Have run it thru one tank of fuel. I can get it to run at high rpms, but will not idle.
Ya, I know its old, it was new still in the box and never run.
I'm just learning, a real beginner. I purchased some old motors and planes, with two Futaba AM radios.
Have no need for the FOX 19RC, still in the box, never been run.
Also a HB, 15 RC, still in the box, never run.
Might be able to use the Fox 35 Stunt if it had a throttle, can one be added??
Thanks

TimC
Yes that's a picture of the motor. Do you think mufflers are still available for it??

fishingnuts, here is a link to a Bisson strap-on muffler. Maybe you could do some measuring to see if it would work. The port dimensions are given in Tech Notes.[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LX8666]Bisson[/link]
You might email Bisson to see if their strap-on will work on your .35S. [email protected]

Just check the tech on the bisson, their size is 29mm x 7mm and the port on the 35 is 36mm x 6 mm.
Still looking.
Thanks

MACS makes a strap on muffler for it but at $40 it's real close to just getting a new motor.

There are a few that show up on Ebay. You might find a parts motor with a good muffler for cheep.

fishingnuts, Pete's Hobbies has a bunch of old O.S. parts. You might give them an email to check on a muffler. [link=http://www.petesrc.com/index.html]Pete's[/link]
Here's the email address: [email protected]
The Mac's looks like a good bet also. Model 6520

Not easily. The intake venturi is flared, isn't it. That makes fitting a throttle very difficult. Plus, I don't remember anyone ever making a throttle for it. It's design and timing actually make it somewhat difficult to throttle. It's most distinctive and valued characteristic is the reason why. It was very sensitive to it's fuel delivery. When needled to give the highest 4cycle possible while flying level, when you hit the aircraft with a pitch up or down, the engine would jump into a 2cycle on it's own. That was with just a needle through a solid venturi. Think what it'd do if you managed to stick a carb, with it's variable venturi, on the sucker. It would drive you crazy trying to get the right needle setting. Plus.... the sucker really was not a solid performer if set to run a fast 2cycle, the way we run our RC engines.

If I were you, I'd trade that Fox off to a Control Liner. It was outstanding at that. It would be miserable as a throttled RC engine.

It was designed to run on fuel with 5% nitro and 25% pure castor oil. And it is one engine that is easily ruined if not fed what it was designed for.

I'm pretty sure I know what your engine's problem is. I think it' probibly just lonely. I have an O.S. S-35, also. And when I mentioned you'd found it's twin brother, it begged me to get them reunited. So, if you'll just send me your engine, I'll do my best to make sure they get together again.

Actually, they are very nice engines if you take care of them. I bought mine new in 1964 and it hasn't quit yet. Just follow the advice given by downunder. These engines were designed for and need castor oil, not synthetics.

fishingnuts,
What downunder said about the castor oil is important with that OS35S. When they are new, just out of the box (no matter how long they were in that box), they need castor oil in the fuel.

They have what we called "hard pistons". There is no ring in the piston and the sleeve wasn't as accurately made as they are today. And the piston is made of harder metal than what we have today. And the sleeve probably is also.

The piston/sleeve breakin is accomplished differently than engines breakin today. The metals and design of that engine requires that you heat the engine up to running temperature, let it "wear in" at that temp for awhile, and then allow it to cool down. And you have to repeat that a number of times.

If you try to shortcut the breakin you risk wallowing out the wrist pin in the piston.

I've worn out so many of those babies I lost count. But did it with gallons and gallons of Fox Super Fuel.

A hard piston/sleeve engine doesn't "break" in, it burnishes in.

It has to be heated up so that the iron of the piston rubs against the iron of the sleeve. It needs castor in the fuel to keep that confrontation from "tearing in" the piston/sleeve.

You need to run the engine in "spurts". The first runs, you get the engine running and make sure it's rich. It does you little good to run it slobbery rich. It is best to simply insure that it's at a 4cycle and then lean the needle to just break into a 2cycle. Let it run at that for over a minute. Then shut her down and let her cool down almost completely. Do this a number of times. About the time you're fed up with it, you need to do it another 2 or 3 times.

You will do nothing but waste fuel and patience to run the engine for extended runs at a constant setting. The technique the good engine guys learned was nothing more than figuring out how long was "enough" to get the engine to operating temp and then how long to let that go on. About a minute or two worked for me.

The castor is very important.

You're completely out of luck at finding Fox Super Fuel. It was the fuel of choice back then because it had 25% oil, and every bit of that oil was castor. Truth is, it's not really life or death nowadays to have that high a percentage. Super fuel could kill those engines just as dead. It wasn't magic.

Look for a fuel that advertises some castor oil content. It will work. BUT

You really can NOT allow the engine to go lean, too lean, or you will hurt it.

And use either 5% or 10% nitro fuel. Don't go higher in nitro.

Those OS35S were made when most modelers were taught to pay attention to needle settings. Fuel without castor have no safety margin on the needle setting for those hard piston engines. You're going to have to pay attention to the needle.

Do it and that sucker will pull stumps for about a year of steady flying. I've kept the crankcase of all the OS35Ss that I used until the shaft bearing was history. They're in a cardboard box. It ain't a small box. grin.............

So here is the drill...............

Use a low nitro fuel that has castor as one of the oils. You can also add a couple of ounces of castor to any gallon of fuel and it'll work.

Crank the engine and immediately bring it to a 4cycle. Then turn the needle in until it just breaks into a 2 cycle.
Lean it out until it starts to slow down. Immediately when you hear it start to slow, richen the needle until it picks back up.
You've just discovered the needle setting near where the piston/sleeve will run safely and break in. Give it a couple of clicks rich for insurance and start the run/cool cycle.

After it is cooled down, crank it and let it run a couple of minutes, and shut it down and let it cool.
Repeat that a couple of tanks.
Test the needle setting every once in a while to see if the "high speed sag" needle setting has changed. If it has and it's at a leaner needle setting, you still have some breakin to go.

Every new flying session, you should always do the following the first time you fire up any engine.

As soon as the engine is running, and you've pulled the glowplug wire, and you're opened the throttle to full, you should open up the needle valve until the engine runs 4cycle. Then turn the needle back to find your high speed setting.

By always taking the engine to a 4cycle, you insure that you never run that first flight too lean. You're just taking it to a 4cycle for insurance, and you're going to set the needle right away to the good flying setting, but you're insuring that you find that flying setting from the safe direction, rich.

Those old hard piston/sleeve engines need the insurance. They're prone to damage if run too lean, especially on the first flight of the day.

The piston is made from cast iron, exactly the same as you'll find in some of the latest Enyas like the 40SS. The liner is made from steel the same as in a ringed engine. I have to disagree with the running in method though because you should never run them out of a 4 stroke for some time. Initially the piston needs to stay as cool as possible until the liner is run in and then start the heat cycling and gradually leaning out to get the piston run in and the cast iron stabilised. The weak point with the S35 is the lower conrod bearing which isn't bushed and absolutely needs a minimum of 25% all castor.

Also make sure you use an Idle Bar glow plug and only an Idle Bar glow plug on that old O.S. 35-S Engine. I've had plenty of old O.S. engines and not one of them liked to run on non Idle Bar plugs. Fox makes a good Idle Bar glow plug.
By the way did I mention trying an Idle Bar Plug.......

downunder,
I actually should have said more than I did....... chuckle......

A bunch of the engines today have ABC or such piston/sleeves, and almost all that're sold in the US are advertised to breakin with only a run or two. I was sort of trying to get across the burnishing deal. And didn't do it very well, did I. I should have added a couple more paragraphs, right? Truth is, some of us Yanks often called a slug piston by the nickname, "hard piston" to differentiate it from a ringed and from an ABC piston.

You know, the hobby shops around here don't carry Enya and I've yet to see them in any of the mailorder websites. They're still being made today? I guess you wouldn't mention them unless you could buy one, right?

You betcha, you're absolutely right about the lower bearing. What I was trying to do was face reality. Over here, most LHSs haven't stocked Fox Super Fuel in years. And I've not seen fuel with 25% castor in my LHSs since.... hmmm..... can't remember ever seeing it in this town, but I only moved here about 20 years ago.

I got to thank you for making me do a search online for Fox Fuel. They do still sell Super Fuel. It's $80/case before you add shipping. http://www.foxmanufacturing.com/accessor.htm

It is 29% castor. About castor.... Today's oils don't have the "safety valve" that castor provides. But what I found with my experience with stunt motors was that you didn't ruin an engine with too little castor, you ruined them mostly with a bad needle setting. And you did it more often with fuel that had no castor. You can kill any engine with a bad needle even when it's running Fox Super Fuel. I've proven that more times than I care to remember. And that was with fuel that had 29% castor in it, not 25%.

I don't mean to cross swords with ya'.... not at all......

BTW, your post kicked me out of this chair and made me go down to the cellar and try to find my OS35S parts........ (I don't got no wine cellar, I got me a engine and parts cellar!!)

Hey Down Under, can I call ya' Down? You can call me DA.... Most of my friends call me DUH. (wonder why?)

Anyway, I just got back from me cellar......... couldn't find the OS35S parts box. And the sucker ain't exactly small either.

I did find some conrod packages. But they were empty. I've used a few of them in my day. If I remember correctly.............

The first ones had no bearings and no lube holes. If you ever launched with a too-lean needle there was a good chance that your engine would come down junk. You can't pull the throttle stick on your TX back and land with a CL stunter. And ain't nothing worse than having an engine you like level out after takeoff and sag. You knew you had 6-8 minutes (they run longer when they're too lean) of torture to endure. If you had a buddy with a towel, and you trusted him to throw the towel accurately, and you felt lucky that the towel draped plane would come through the landing and...... and...... whatever...........

We often swapped SuperTigre conrods into the 35S. We also drilled lube holes. But I think that for awhile OS sold bushed rods. Don't know that for a fact, but I was looking for my parts because I was positive I still had a couple.

I do remember having more problem with my engines at the top of the rod. Seems I used to have more probability of the wrist pin wallowing in the piston than the low end of the rod ovaling out. But that was many years ago. 30?

I used to buy RedMax directly from the factory..... chuckle.... "factory"..... the factory was in Fred's backyard originally, and then in a little industrial park. He talked me into using a blend of oils. It worked in my OS35S like gangbusters. It was actually better because with LESS castor an often used (and mine were OFTEN used) engine varnished up inside slower. Varnish on the outside kills the cooling, but it also hurts inside. I never wanted to back down to no castor, but less was obviously better. And I saw no real difference in time on parts with a half-and-half blend of oil.

Whatever.... good talking with you. You're always good info and great to discuss with, mate.