Cox Green Bee

The engine is disassembled and taking a bath right now. The acetone already looks like river Liffey on St. Patrick's.
The glow head sadly is indeed gone, as the seller said it was, I found a replacement in my spare parts box. The needle valve is all gummed up, the fuel intake tube is petrified and the spinner screw is all corroded, as is the reed, but that's fine, it will all clean up or be replaced. The gaskets are shot, no worries, I would replace them anyway. The cylinder is a single bypass port. I was expecting a dual-port, maybe I confused it with the Killer Bee, not sure.
There's massive axial play on the crankshaft, I will have to pull the drive plate tighter into the crank, which I now thankfully know how to do.

Be careful with the backplate - it is not brass but a rather strange alloy with a sealant coating /plating. I think the alloy is Zamac or Mazac. Anyway, it is not robust and doesn't like acid or alkali cleaners.

A single by-pass cylinder is standard for a Golden Bee. Should be a #2.
I agree with Ian. The "brass" finish on the alloy backplate can easily be lost, so be careful with it. Don't try to polish it with abrasive because you'll just remove the plating.

Hi D.G. and congratulations on sourcing a Cox engine that you're sure to have a lot of fun with! That engine is basically a Babe Bee with an additional 3cc's of fuel-capacity.. and the ability to fly inverted/stunt (control-line).

You may want to replace the fuel-line with the same (vinyl) type as the original. Some modelers choose to reinstall/replace the tiny "coil-spring" which is internal to that vinyl fuel-line. Whatever the case; be sure to orient the "pick-up" end of the line.. at the outermost position of the tank/bowl.. in relation to circular-flight. This is generally at the 9:00 position when assembling the tank with the needle upright.. and while viewing the inside of the backplate. The (Zamac/Mazac??) pot-metal backplate is a part that you'll want to preserve. They're no-longer available "new".. and are superior to the replacement (plastic) type. Take care NOT to over-tighten the 4 "fillister-head" 2-56 machine-screws which thread-into the rear of the engine's crankcase.

The copper (beryllium) star-shaped reed can be re-used.. if it's not creased or porous. I have cleaned them by pinching in-between two small squares of 400-600 grit sandpaper.. and gently rubbing.. a few strokes at a time.. and checking. Once the metal looks clean/clear.. that's enough. Be careful not to bend/crease the reed. It's really better if you can re-use it.. along with its "circlip" retainer that it was designed for. A replacement mylar reed is .003"-.004" thicker.. and may not work correctly, without thinning-out the circlip.

The tank-bowl's vent-tubes work quite well for stunt. The Sig Manufacturing Co's. "Skyray" is a great platform for that engine! The kit is still available from Sig for less than $20 (US)

https://sigmfg.com/collections/control-line-kits/products/sig-skyray-kit



Best of luck!

Nice find. As Ian said, the backplate is made of an alloy, referred to zamak (or was it mazak?). Anyway, it is mostly used for decorative parts and fittings. Base material is Zinc, other components are aluminum, magnesium and copper. It is easy to cast in complex shapes but not very strong. Without plating, it is easily corroded, and it's natural colour is kind of a dull grey. I have seen them polished to mirror finish though. The material is almost impossible to repair, although I would *think* small holes and cracks could be soldered maybe?

A word of warning, when you start to remove the fuel hose, be very careful. you might want to try to split the hose with a knife, or try to carefully pry the hose off with a small screwdriver or such. I am telling you this because I am still kind of p'd off at myself for breaking the fuel nipple off the otherwise perfect backplate of my late '60s QZ

The green stuff is probably just nitro that has absorbed air humidity. I am pretty sure it is not corrosion-related. Fortunately all the parts you need are available. The Golden Bee is equal to Babe Bee when it comes to power, but a #1 cylinder would make it equal (or close) to a Black Widow.

I still don't have a Golden Bee in my collection, seeing yours make me want to put a want ad on the forum again

roddie wrote:
You may want to replace the fuel-line with the same (vinyl) type as the original. Some modelers choose to reinstall/replace the tiny "coil-spring" which is internal to that vinyl fuel-line. Whatever the case; be sure to orient the "pick-up" end of the line.. at the outermost position of the tank/bowl.. in relation to circular-flight. This is generally at the 9:00 position when assembling the tank with the needle upright.. and while viewing the inside of the backplate.

I'm not going to use this engine for CL flying, so I moved the fuel pickup line down to the bottom of the tank. After all you guys told me about how brittle the backplate is, I'm a little terrified - the fuel line was very hard so I just yanked it with pliers to make it move. Hope I didn't hurt the nipple

dirk gently wrote:

roddie wrote:
You may want to replace the fuel-line with the same (vinyl) type as the original. Some modelers choose to reinstall/replace the tiny "coil-spring" which is internal to that vinyl fuel-line. Whatever the case; be sure to orient the "pick-up" end of the line.. at the outermost position of the tank/bowl.. in relation to circular-flight. This is generally at the 9:00 position when assembling the tank with the needle upright.. and while viewing the inside of the backplate.

I'm not going to use this engine for CL flying, so I moved the fuel pickup line down to the bottom of the tank. After all you guys told me about how brittle the backplate is, I'm a little terrified - the fuel line was very hard so I just yanked it with pliers to make it move. Hope I didn't hurt the nipple

It's so easy to remove an age stiffened fuel line by simply passing a heat gun over it on low heat a couple of times then just wiggle it off, not straight pull.  Remove the spring filter and soak both in Simple Green while passing a small brush through the tube.  I have done 50/60 at least this way and always re-use them.  Adds up at this volume when they run a couple of bucks from retailers.







However, they do take a set and it may make it difficult to re-attach the tank to the backplate.  If that's the case, just position the pickup tube for C/L or R/C/free flight and use the heat gun again to slightly heat the backplate/pickup and reassemble.  The warmed tube will form correctly to the fuel tank.  Ensure the spring/filter is in place.

Congratulations on your purchase, the Golden Bee, probably my favorite Cox engine.

Here's something I've never seen before: the fuel pickup line swelled up 5 times or so, and got all jelly-like in the acetone bath.



It then shrunk back some after drying up. Not a problem, I have a replacement, and I don't have enough engines for the fuel line cost to amount to any significant sum. I will surely do it your way next time, rsv1cox.

dirk gently wrote:Here's something I've never seen before: the fuel pickup line swelled up 5 times or so, and got all jelly-like in the acetone bath.



It then shrunk back some after drying up. Not a problem, I have a replacement, and I don't have enough engines for the fuel line cost to amount to any significant sum. I will surely do it your way next time, rsv1cox.

Acetone and plastics/etc do not mix.

Brush set is cheap on ebay.  I use that Harbor Freight heat gun, but they can be found less expensive but may not have dual heat ranges.  I couldn't get along without either one.

On the hose i just clip it at the nipple to give it some relief and bend/snap it off . Sometimes the wire can bee a PIA to get out a soak helps, then i just push it out with a pick. A soak for only 15 min.s in some Hobbies #9 gun cleaner does wonders for the back plate Hope the engine runs good for you !!

I do own a double setting airgun, and if even the lower setting is too much, I can use a hairdryer. Anyway, I replaced the fuel line and the engine now runs
Video of the maiden run:



As always, thank you for all your support!

Sounds pretty good , maybe after a few tanks through it it will bee more steady> it hard to get all the gunk out when that bad , but it does run

Nice Job! Seems to run good and strong.

Good job on the clean up. Runs nicely.