The flying monkeys got me...

Helis and fixed wing

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AMA Intro Pilot Instructor

Wednesday, October 21, 2015

RCGF 10cc Gas Motor Issues

UPDATE: Its running fine!  Read the UPDATE.

It's old news that I selected the RCGF 10cc engine for the Sukhoi SU-26. My initial impressions are quite good, but more because of the great support I am getting from Joe at RCGF USA.


I have always felt that most RC products are over priced. But both the Evolution and the RCGF 10cc motors were priced at $199 shipped. I chose the RCGF engine because it wasn't a pressurized tank system (a glow converted engine), it has a ringed piston,  it used the same fuel mix as my DLE 30, and it seems popular, well constructed, and simple in design.

I still like all of those things. The engine arrived quickly with a nice personal hand written thanks from Joe. Well packaged and protected. It installed easily, and I had the entire thing from ignition battery, to kill switch, recvr/ign manual switch, engine and electronic ignition installed in under a couple of hours. I am also using a Quickfire filter. I took the battery packs from the 30cc MXS-R since HK just got my order shipped yesterday.

Yesterday I tried starting it, it just didn't seem to be getting fuel. If I primed the lines it finally spun up but quickly quit. I wasnt sure if it was the pump, the filter, or the vaccum. It's almost never the spark. I quickly discovered a massive fuel leak in the tank from a pinhole in a corner, fixed it by replacing the tank, but thats not the problem. Made a mess of the airframe. Tried starting again, no joy. Gave it a break overnight. Was the pump position an issue? Was it too high? Should this matter? Maybe the vacuum is inadequate for the Quickfire; I can take it out of line and see, move the pump... Is there yoo much fuel line? Shouldn't be. What else could it be?

This morning I started where I had left off. I took the Quickfire out of line, still no joy. I moved the fuel pump lower (I really don't think that changed anything), primed the lines and put the Quickfire back in line. This time is rewarded me with a couple of 15-20 sec runs before it just died, then nothing. Well, we know its working, getting fuel, but why does it stop? I decided to check the spark plug to see if there was some reason the engine could not sustain enough compression to keep fuel coming.  I had done everything else I could think of.

When I removed the spark plug it came loose a lot easier than I expected, and there were metal filings around the threads. I checked ignition spark and it was hardy. I went to put the spark back in and wasn't surprised that it would loosely thread, not completely seal, it kept turning on finger tip pressure, and I could pull it out easily. The threads were stripped in the cylinder head and I hadn't even screwed it back in. I have to say, when it did run, it sounds smooth and sweet! It gave me chills, I was so excited. It made it clear I will never build another electric again!



Bummer, though. I think it was having trouble because the cylinder wasn't sealed during the compression stroke but for that couple of times it ran, and then only briefly. But who knows.

Now comes Joe. I called him and he was great, apologizing without blinking an eye,  and asked me to send the engine back, he would get it running. He noted there have been some manufacturing issues on some of the engines with tapping the cylinder heads, and my issue was not unique. I uninstalled it and mailed it out this afternoon.

I don't expect perfection. Remember, "Its always something." What keeps me a fan of this engine id how sqeet it sounded, and that when it had a problem I spoke to THE man and he is on it. Can't do better than that.


My usually well organized shop is a mess, I was so focused on getting her running. Back and forth to the garage, who has time to keep things neat?



So now we wait... 

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