.049 Restoration

Testors McCoy .049 Update

It’s been close to eight months since my first blog post which was the cleaning and restoration of my Testors McCoy .049 engine. If you follow my Facebook page you probably know that I got some fuel for this engine Thursday I think it was. The fuel I ordered was SIG Champion 25 which has 25% nitro and 20% oil (1/2 castor and 1/2 Klotz synthetic). I tried to start my engine the first time Friday night.

As I was flipping the propeller with a chicken stick, the chicken stick went and hit the needle valve which bent it sharply. As I carefully tried to bend it back enough to be usable, it sheared in two with it being fully screwed into the engine. I had to file a slot into the end of the needle and use a screwdriver to back it out. I then soldered it to some brass and went back to starting the engine.

I flipped the engine for a long time with no reward; the engine wouldn’t start. So I did the only thing I could do, I grabbed my electric starter. I used the starter and on my third try, I got the engine running. It ran for about 2 seconds and then quit. I didn’t get it started again that night.

Sunday afternoon I had some time to try again. I first used my chicken stick for about 45minutes. This time I got some really good ‘pops’ with the occasional quick sputtering of the engine lasting only a second or so. Again I grabbed my electric starter. I got the engine running again using the E-Starter. It ran for probably 5 seconds and then died. I tried for a while longer until my glow plug was dead.

Yesterday morning was the last time I tried to get the engine running. I used the chicken stick for about 20 minutes with promising results. Although I never actually got it running, it would turn over on its own about a dozen revolutions and then stop. It did this very often. Maybe every other flip or so. While trying to start it yesterday I had to continually stop, plug in glow starter to charge, and come back in 15minutes or so to try again. My glow starter is really old and doesn’t hold a charge that good so I’m always having to deal with it dying. So when it died and I plugged it in to charge, I went to find a better way to make my glow plug glow; something that would never die and will always be constant – a power supply.

I started out with small power supplies. I would rig then to my 1/2A glow clip and attach the clip to just the glow plug so I could see if it would make it glow or not. I would very quickly touch the center of the pole of the glow plug with my clip and then very quickly remove it. I did this to see if it would be too much for the glow plug to handle. If it didn’t shine red hot instantly I repeated the process multiple times but each time leaving it connected slightly bit longer to see if it worked. I did this to two power supplies (one with more output than the other) and neither one would even make it glow a little, so I got my third sized power supply. It was just about half an amp more output than the biggest power supply I had already tried. I hooked it up and began my process. I connected the clip to the glow head and extremely quickly (probably less than 1/10 of a second) touch the center pole of the glow head and removed it. POOF! The glow plug’s nichrome wire instantly vaporized in a flash of red-orange flame. I instantly knew I was screwed :(

I knew I couldn’t repair it. I looked online to see if I could drill and tap the head for a regular glow plug but everywhere I read says that it messes up the size of the combustion chamber and it causes the engine to not run well. So I’m really upset. I’m mainly mad at myself, but also upset that I screwed up something that’s pretty hard to find.

I would order a new head off of eBay, but I don’t have the money right now because I have spent it on two new Cox .049 Sure Starts from someone off of RCGroups. So those should fill my need for a 1/2a engine. I will also be putting one on my first balsa scratchbuild that I plan to start sometime after Christmas. . .

One thought on “Testors McCoy .049 Update

  1. Sounds like you had battery, glow head or rear gasket seal problems. Lay off the eletric starter on any non-ball bearing engines as this abuse quickly results in sloppy crankcase/crankshaft clearances and more performance issues. The sig fuel shouldn’t be an issue. Are you sure about NV/fuel line/
    spraybar debris issues?

Comments are closed.