Hi everyone,

I had got some spares and dismantled my Cox(s) in 2018, and they were lying in a box since then.
Last month I got some more parts, and decided to overhaul one today, having earlier cleaned it up externally.

Here's how it went.

1. Dismantling. Not to be attempted without the Cox 049 spanner.

2. Piston conrod ball joint reset.

Over time and use, the ball joint develops a little play. (There's no gudgeon pin)

There's a special tool for this. There was barely perceptible play, which I removed.

Edit: For some reason the pics are upside down. Unable to correct

3. Parts replacement

Old parts on the left, new ones on the right.

The O ring for the tank venturi to backplate joint had deteriorated and completely gone! Only the black colour remained.

The tank to crankcase gasket broke into pieces when I tried to remove it.

The fine spring that prevents the fuel tube from kinking was gone. Wonder how it was lost!

Copper reed replaced by a mylar one.

Though the reed retention clip seemed okay, replaced it with a new one anyway.

4. O ring

This is where it fits.

5. Tank innards

Fuel pickup pipe with anti-kink spring insert.

Mylar reed and clip

6. Reassembly

Cox 049 spanner essential for this. Any other tool will end up distorting the cylinder. And the engine will never run again!

7. All done. Like new now.

BTW, for the preliminary cleaning of the exterior, DON'T USE ANY CHEMICALS OR ABRASIVES.

All you need is hot water, a toothbrush and some green soap (like Hamam, Rexona etc)

Long (50+ years) ago, we used to mount Babe Bees without bolts.

With rubber bands! As a crash damage minimisation strategy.

Like this...

(Sorry about the inverted pics. Even rotating the original didn't fix it  )

P.S. Ah ha! Took a fresh pic with the ipad turned 180 degrees. That cured it!

Nice work! 

Cox spares are pricey though

Its very strong engine .if its plug cooling fin bent you can not do easily straight. good to see old model and engine .

2nd Cox overhauled and started.

This one is a QZ (Quiet Zone), having a muffler.
Also has an 8cc stunt tank that permits inverted flight.
It is slightly newer than the first one, being only about 35 years old!

Came back today morning from a two day visit to a childhood friend and fellow aeromodeller in Ahmedabad. Found two Cox 049s that needed resurrection in one of his boxes.

Was able to restore one to its former glory with a complete overhaul. Has excellent compression, and surprised me by starting on the very first flick!

Attached are 'before and after' pics. The second Cox is undergoing a refurb.

Nice and shiny now! 

If it stops after half tank, or needs constant fiddling with the needle, chances are that the gasket between the end of the tank venturi tube and the backplate is worn out or damaged. Replacement not easy to get (Cox International or Densmodelsupplies, £ 1.50 for a pack of 3 if I remember).

So I had to make one! (The white one)

This one needs a new glow head, head gasket, reed, backplate gasket and venturi gasket.

Fortunately I had the first three, and was able to make the other two.

Restoration complete!

Had an original Cox adaptor head for usual glow plugs.

Some experimenting with shimming the plug for correct depth was needed, then it ran just as it did with the normal Cox glow head.

That's all for now till the next Cox overhaul.

The purpose of this thread is to reach out to people (if any), who still have old Cox engines and wish to get them up and running again.

Looks like you are the only COX engine fan here

I think there are many fans! I am one

A few things about Cox -

1. Models are low cost
2. Lots of fun to fly
3. Very low fuel cost
4. Nothing can beat the high pitched whine of a Cox engine!

http://www.rcindia.org/gas-glow-nitro-planes/hornet-049/

Nice to see your models Sir, I too have built 2 models for the 049 engine.
The only issue is that the engine requires special hardware to maintain and start.

I have 2 engines lying idle and unable to use as i donot have the glowhead clip to start.
Looking for one.

Quote from: sbajare on August 21, 2023, 10:39:50 AM
Nice to see your models Sir, I too have built 2 models for the 049 engine.
The only issue is that the engine requires special hardware to maintain and start.

I have 2 engines lying idle and unable to use as i donot have the glowhead clip to start.
Looking for one.

I use an ordinary clip! The "chimta" type. Iyer-ji has adapted the head to use a standard Glow Plug

In the 80's Mr. Kalsi had made lots of these clips. He may still have some

where can I buy the cox engine?

Quote from: Aodz on March 24, 2024, 12:04:28 AM
where can I buy the cox engine?

Taksh has several new ones for sale.
Send him a PM.

Hi Aodz,

I have little used COX engines for sale. U can msg me on 9988279077.

Thanks