It's all this forums fault.

[ebeneezer]

I dont know, I join this forum to ask a couple of questions relating Cox 0.49s and freeflight model size.
What happens? I meet loads of really great people who get my juices flowing, I get all the Cox engines off my Dad and try to run a couple
They all look in reasonable condition. The only ones Ive had any luck with are my Two Babebees and a Peewee.
All the others are siezed solid. Given the availability of spares, I'd like to try to restore them.
First off is there a way to tell the difference between an 0.49 and an 0.51 short of measuring the bore. This I'm reluctant to do, in case I mark the bore.
Do I then soak them in a freeing oil, try to turn them over if I can, strip and inspect them.
Other than wear, is there anything obvious I should look for?. Is there a good book devoted to Cox engines? I should invest in. Finally What about specialist tools, what do I need and is there some I could make? I am a bit of a metal basher with a moderate workshop. I dont want to plunge in blindly encase I do some damage.

Cheers

[ebeneezer]

This Is the first one I want to restore. I just like the silencer shape any ideas where its from?

[microflitedude]

.051 pistons will have at least one ring or groove around the piston skirt.

[fit90]

That is a Hiscott muffler. It is part of a throttle arrangement. It was to be used in conjunction with a new Medallion venturi body with a rotating spray bar. Some time over the weekend I will post a pic showing all the parts. If I still have the instruction sheet I will post it too. There should be a pin sticking out the front part of the muffler between the silencer and cylinder. This is part of the throttle assembly. I think the pics and instructions will do a much better job of explaining than I can.

Bob

[SuperDave]

Eben:



We'll glady accept responsibility for enabling your interest in Cox engine; that's what we do!

Seized Cox engines can usually be freed by disassembling them and cleaning the parts with solvent such as Hoppe's #9 Gun Cleaning solvent. Proper disassembly requires the appropriate Cox wrench lest damage be caused. Do NOT use pliers to disabbemble an engine. Doing so can cause permanent damage to vital parts and significantly decrease the value of your engines.

Accumulated castor oil residue is the most common culprit in cases of engine seizrure. This subject has been covered countless times here. Detailed instructions may be found.

We have several vendors that can supply parts and tools
Cox International - Model engines and parts being one of them. Check out Bernie's very informative site for further information. Look for "Trouble-Shooting Guides".

[ebeneezer]

I think you are Right. There is a pin sticking out the front muffler. it will be interesting to find out more. I will see if I can track down more bits, when I know what I'm looking for.
Thank s for your help.

[John Goddard]

Yo Ebz
Not sure you're easily lay your hands on gun oil here but...
I've freed half a dozen this year the 'free up 101' I've
Found is,- Head and cylinder off, the TeeDee in your
Photo take the rear crankcase plug out then soak over night
In Plusgas if you have some or WD40 if not.
If the cylinder doesn't want to comE off chuck that in for the soak
As well.
Next day stand the crank case on it's end on a block of wood,
ensure the prop bolt is screwed right home then give it a tap
Or two with a mallet or soft hammer.
The crank should then turn. I've not encountered a cylinder
That wouldn't pull off the piston after the soak.
If the engine in question is a bee type take the tank off
Instead of the crank plug and do as above.
Good luck.

[RknRusty]

Ha! We converted another innocent over to the Cox side.

This forum and the rcgroups.com 1/2A forum is pretty much the book, as well as the guides at coxengines.ca. We have most of the guides stickeyed here at CEF. Use the Google search box on the top left for the best results. And like any site, you can search it with Google-Advanced search by entering the web address in the domain box. Leave out the protocol prefix. For example you'd enter "http://coxengineforum.forumakers.com" or "rcgroups.com" in the domain box. All results will be from the site you tell it to search.

[andrew]

Ebz ---

If you haven't read it, check out the thread Box-o-engines by Kim. The first page shows his engines in raw form and the second page shows one that has been cleaned up (it looks like a new engine). If yours looks as good as his when done, you'll have a real showpiece.

andrew

[Ivanhoe]

Rule no.1 Do NOT attempt to unscrew the cylinder on a stuck engine! you will twist the conrod out of the piston.(Been there, done that!) Get the piston free BEFORE you attempt to unscrew it, or you will have one really screwed engine!
I have always soaked stuck engines in new glow fuel as a first attempt, fit a prop and GENTLY rock it back and forth, if the piston still won't move you can go on to the more brutal methods listed above
Just a little note also, 0.49 is 8cc, Cox .049s are .8cc,

Wilf

[SuperDave]

Wilf's advice, as usual, is solid and worth observing.

To the degree possible, let the solvent do it's job by giving it lots of time (days or weeks) to throughly penetrate the castor gum that so often seizes frozen parts. Force will cause damage and impatience is your worst enemy.

In the extreme, there ARE other methods but they should be done only by experienced hands. Start with the simple methods descripted then, if you are unsuccessful, we can describe others.

(Yes, I HAVE used pliers but under VERY controlled conditions)

[ebeneezer]

Thanks Guys Ill let you know how I get on.

[John Goddard]

Yo Ebz
Not sure you're easily lay your hands on gun oil here but...
I've freed half a dozen this year the 'free up 101' I've
Found is,- Head and cylinder off, the TeeDee in your
Photo take the rear crankcase plug out then soak over night
In Plusgas if you have some or WD40 if not.
If the cylinder doesn't want to comE off chuck that in for the soak
As well.
Next day stand the crank case on it's end on a block of wood,
ensure the prop bolt is screwed right home then give it a tap
Or two with a mallet or soft hammer.
The crank should then turn. I've not encountered a cylinder
That wouldn't pull off the piston after the soak.
If the engine in question is a bee type take the tank off
Instead of the crank plug and do as above.
Good luck.

When I said tap I really mean tap. Not tap as in ball reset or tap/CLOUT as in prop driver removal.
Last time I did it I used a toffee hammer.

[RknRusty]

Thanks Guys Ill let you know how I get on.

Hey, Ebeneezer, did anyone mention heat? If so, I missed it. But I think it's okay to warm it up with a hairdryer to help loosen it. Just don't ignite the close by solvents with the sparky little motor in the thing.

[fit90]

I hope this is usable. It is the highest resolution I can scan and post here. Some pics are on their way.

Bob

[proctor]

This Is the first one I want to restore. I just like the silencer shape any ideas where its from?

Have you noticed what looks like a pop rivet, presumably blocking the pressure tap on carb body. John

[fit90]

In the last pic I tried to show how the spray bar is flattened around the hole. This whole assembly is an updated copy of Cox's original muffler restriction/spray bar rotating system used on early Medallions.

[fit90]

This Is the first one I want to restore. I just like the silencer shape any ideas where its from?

Have you noticed what looks like a pop rivet, presumably blocking the pressure tap on carb body. John

I would bet that is someone's attempt to make the venturi body pressure tap retain fuel tubing better. Just a guess.

[Kim]

John[/quote]

I would bet that is someone's attempt to make the venturi body pressure tap retain fuel tubing better. Just a guess.[/quote]

Yeah, you can get a new Throttle Body from Bernie at: http://coxengines.ca/cox-.049-carburetor-body.html . He also has the wrenches needed to do dis-assembly on these little rascals.

For the intake venturi on Tee Dee's, you can grind down a 9/32 ignition wrench (not sure what the term for it is over there) to back it out. I've got another one with the jaws at almost 90 degrees to the handle that I use a lot, but couldn't find it at the moment. For me, this seems to give a lot more control over the tightening of the assembly than the factory wrenches.



With those parts out of the way, you can hit the shaft with the oil recommended (or fuel) and get it close to home right away.

I open the engine up as much as possible-glowhead and carb body removed along with the tank or rear case plug (these can be stubborn and often make me wait 'till the nest step). After a night's soak or so, I bolt on a prop, hold the engine with a leather glove, and put a heat gun to the head and case, just enough to get it pretty warm, then gently put some turn on the prop.

This has worked on all of the engines I've attempted to break loose. As stated above, most if not all, of these engines are stuck from petrified castor, and the heat softens this stuff in tight areas where penetrating oils may take forever to reach. You DO want lubricants on either side of the parts as they start to move.

While it's still warm you lay a thick straightedge through the notches in the back plug and see if it will budge. A piece of hardened steel is often more effective here than the factory wrench. You need it to fit nice and tight in the notch to keep it from climbing out as you torque it.

Soak and swab everything, and oil it up good for reassembly, and it ought to light right up. Pay particular attention to the needle valve area, and the tiny holes in the carb ring and venturi body. They ALWAYS plug themselves up after a long sit, and won't deliver fuel to the engine again 'till they're clean.

Just some stuff I do...

[ebeneezer]

Thanks Kim you've been a great help, By the way, I love the Bob Seger quote. I'm one of those who went, and wished they hadn't. But it was fun going.

[Kim]

Thanks Kim you've been a great help, By the way, I love the Bob Seger quote. I'm one of those who went, and wished they hadn't. But it was fun going.

You're welcome! I hope it helps in your restoration.

Yeah, I've managed to hit all four phrases in Mr. Seger's verse...several times, but I'll still take a bad crash over parking on the porch !!!! It at least gives you great stories to tell !!!

[ebeneezer]

Hi Kim.
Me too, I decided to see what it was like to fall off my beloved Harley. I wont do that again, wont ride a Harley again either. Like you say I still Have the great memories. Anyway enough of that, back to Cox engines. Having read all the comments about reconditioning a Cox engine, I decided I'd strip my 0.49 Sure Start, the one I want to convert to a diesel to learn. It came apart just as you guys suggested, and I have to say, it was a thing of beauty when apart. I made some brass shim thrust washers to reduce the end float and guess what. When cleaned and reassembled, just turning it over you could feel the difference. I swear it felt like it had more compression and it felt less sloppy. Unfortunately I should have put my Taco on it before stripped it, I swear now it runs faster, it certainly starts better.
Now to convert it to diesel.

Thanks.

[ebeneezer]

Hi Kim, Just read your quote from John Fogarty. Dont recognise the lyric. Next to Hendrix, CCR are the best band to come out of the States. So full of life and hope. Still that was the magic of that era.

[Kim]

Hey Eb,

Yeah, I mis-spoke with that statement of "taking a bad crash over sitting on the porch", intending to preface it with "the threat of a bad crash". I'm certainly not complacent about bike wrecks! At my age the healing process has slowed considerably, and I always wear an armored jacket and helmet when I ride !

I've dabbled in machine work just enough to appreciate the incredible tolerances and metal treatment involved in making these little engines run...and this goes exponential when I consider the fact that they were mass-produced by the millions!

As a side story, my machine tools instructor was an Old-School WWII vet named Franklin Myers. One of his favorite stories was his disdain for engineers that arbitrarily called for really close tolerance on non-critical parts. He said he loved to get them on a milling machine or lathe, and let them try to make a part, giving them a forceful example of just what .0010 looks like!

Anyway, glad to hear you're having fun...and it just goes on with these engines ! Yeah, my tach and camera are almost glued together! I don't retain numbers very well anymore, and either record them with my camera or make notes on my left hand...which doesn't work well when it's covered with castor !!!

Beware the Cox Quick-Sand !!!!!!!

[Kim]

Hi Kim, Just read your quote from John Fogarty. Dont recognise the lyric. Next to Hendrix, CCR are the best band to come out of the States. So full of life and hope. Still that was the magic of that era.

It's from his first solo album "John Fogerty" (nick-named the "Ole Shep" album for his little dog who shares the cover photo) in 1975. I was still fairly young, and "Almost Saturday Night"'s theme of anticipation of an adventurous night out with friends really landed on me.

I had a pack of great friends (somewhat similar to these days), and we always had a hoot when we could get together. We were all growing up, with the scheduling conflicts of jobs, spouses, and girlfriends, so when the timing tumblers lined up to let us meet, it was really a special deal.

I often found myself riding home late at night on my Sportster, thus the verse about the "Night Train taking me home", and my current bike is a Harley "Night Train"...so it rolls on.

Old guys and their memories...guess I'm there !

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