Recent engine acquisitions

A little while ago I was given (yes, given, can you believe the generosity of some people!!) some engines, among them this nice little Space Bug Jr.

It was not stuck but did not turn freely either so I didn't force it. The needle was of the later type and one of the mounting ears was cracked a little. Some "battle scars" here and there, but the cylinder is in perfect condition. Just the way I like them It makes a great addition to my collection, this is my first "old school" cast crankcase Cox engine. For some reason, I like these old engines to show their age somewhat and I love cleaning and fixing them up (or maybe this is just a way to rationalize being too cheap to buy NIB ).

Here it is "as delivered":



My only spare "old style" needle valve was bent from two spots. I used a 4" adjustable wrench and a junk babe bee backplate to straighten it. An adjustable wrench is a good tool for this, as the jaws are smooth and you can pre-set the jaw gap before bending. With pliers I tend to squeeze harder as I bend harder, and it is easy to leave marks on the work piece. Anyway, it is not 100% perfect, but it goes freely all the way in, and I can't see it being bent when it is installed. Glad I saved that old needle.

Nex step was to remove all I could. The cylinder wouldn't budge, I didn't force it as it has very thin walls:



Fast Forwarding past the hot ultrasonic bath. Metal parts took a bath in hot ethanol, plastic parts had water and dishwashing detergent (hand wash kind). I poured the crankcase full of oil, turned the crank over so that the oil went everywhere, refilled and left the engine on the glass jar nose down, allowing the oil seep through the crank bearings.



All the parts were first dried off, it was easy as they were warm after the bath. Then I either wiped them with oily Q-tip or wipe, or dipped them in oil.

Next step was reassembly.



The reed assembly had three parts, a ring and two copper "leaves", one very thin and the other a little thicker. The copper parts separated in the bath, so I am not sure of the order they were originally, but my "common engineering sense" advised me to put the thin one against the intake.



There were no gasket between the tank and the crankcase, not sure if there should be one. The plastic parts cleaned up very nice in the bath.



Here's the end result. I like it



As a final step, being me (a test engineer and a science nerd), I filtered the ethanol bath through tissue, here's what was caught:



There were some silica (sand), some solid castor crud and even a couple of small metal shavings. The sand is probably off the exterior surfaces, but there were some on and around the exhaust ports too.

There were a couple of other engines in the same lot, more about them later