JC's Planes and Projects

The Giant Su-Do-Khoi (GSDK) just before the first flight.

The first flight of the GSKD was much anticipated because I had struggled to finish the kit and very much looked forward to exploring it's flying capabilities. I finally got the plane together, loaded it into my trailer, and towed it to the field. It was a hot, humid, and calm, Michigan summer day. The Moki was brand new and had never even been started. Of course I knew that it was ill advised to break-in this engine in the air, but as I had alluded too earlier, I had lost patience and wanted to fly this bird.

I had heard that the way to start the Moki was to prime it very wet and back-flip the prop. This did not work for me and I back-flipped till I was red in the face. Another modeler came to my aid with a heavy-duty starter and it fired-up. I had never run a glow engine bigger than a .90, so it was a thrill to see this brute in action. I just set it very rich and ran 16-oz through it on the ground in a variety of throttle settings. It ran fine, so I fueled it up and prepared for the first flight.

I found that I could hand start the new Moki if I flipped it forwards through compression at idle. This will sometimes result in a mild kickback, but if you use a chicken stick this is not a problem. In fact, with a good prime it will nearly always start on the first flip! I got the Moki running and set up rich. I taxied the GSDK out on the grass strip and tested it's ground handling. Despite the very springy gear (Morris included the thin gear from the .60-.90-size kit and instructs you to add cross wires - I didn't) it handled very well on the ground. I turned it around into the wind and slowly added throttle. The plane accelerated smoothly, lifted its tail, and started a shallow climb-out at less than full throttle. The smoke trail left by the rich Moki in the calm air was quite dense. A crop duster would have been envious!

At altitude I was able to observe trim. It was very nearly perfect; in fact, it was the best-trimmed airplane I have built. Just a "beep" here and there and it was perfect. The airplane flew very smoothly and slowly at half-throttle. At about five minutes into the flight the Moki died. No problem…and one that I had anticipated without fear. From pattern altitude I was able to make a nice easy circle to a nice quiet landing. The GSDK glides very well and this is why I had dared to break-in the engine in the air at the risk of deadsticks.

Once back in the pits, the propeller was found to be loose, as was the fuel inlet banjo. The latter was most likely the cause of the deadstick. I allowed it to cool and once again took to the air. After five minutes the Moki started acting funny so I immediately set up for a landing. Once down I taxied back to the pits and attempted to kill the motor. It wouldn't die! I ended up pinching the fuel line to kill it. Examination showed that the carb was loose in the barrel. So loose, in fact, that the tension of the fuel lines was most likely the force that kept it from parting altogether. Well, I had dodged two bullets and was thankful. It was time to go home give the plane a good inspection before tempting fate again.

The next dozen flights went well with some mild aerobatics attempted. The Moki was running very rich, but still had a tendency to lean out excessively in the verticals. In fact, I had to run the Moki in a stuttering-rich state on take-off to avoid potentially starving it in verticals as the flight progressed. I was convinced that I had a fuel flow problem and was starting to wish that I had fitted a gasoline powerplant to this ship. I fitted a Perry regulating pump and it was a disaster! I could barely get the engine to run with this pump and spent an entire evening trying everything. I was exasperated. It was the first flightless trip to the field for me in three years.

When at a loss, I often seek the advice of the gurus of the Internet. They did not fail me. The responses could be put into three categories: Moki's are crap, I should have used a Cline regulator, and disassemble the carb/needle valve. I chose the latter, although I confess to a strong feeling at the time that the first category was true as well! I took apart the needle valve assembly and found some hard, congealed, varnish in the inlet banjo. It was a miracle that this engine ran at all! I cleaned it up, removed the Perry pump, and it has run like a Swiss watch ever since.

I only put two-dozen flights on the GSDK before the cold weather set in. I can say that it flies very well and will definitely remain in my stable. The Moki provides unlimited vertical, yet it can hang in the air at one-third throttle and land at a crawl with the tail-wheel touching down first. It is large and easy to see, and flies almost as if it is in slow motion. It will knife-edge very well with that slab fuselage and has only a very slight tendency to pitch to the wheels. This was easily mixed out. Inverted flight is a dream with only breathing on the stick required for level flight. I think that the best complement that I can pay the GSDK is that it flies a lot like those "perfect" airplanes on my RealFlight simulator. I am looking forward to flying the GSDK a lot in the 2003 season.

So, you may ask, "was it worth the trouble?" The answer, after much thought, is NO! The "kit" is an under-engineered collection of sticks and an absolute rip-off. The end result of a good airplane does not change this. I am very proud of my GSDK, but I can give none of the credit to the manufacturer. I think it is, as I said in the first page of this web review, my "renewed grit to build it and build it right" that I am most proud of.