agexpert

My Feedback: (1)

I am currently flying 3 planes, but like most people, I have a favorite. It's a H9 super stick 40 with a magnum .46 xls engine. I am still learning and quite paranoid about fuel so I always top-off the tank after 2 flights....sometimes 3. My flights are generally short, 10 mins or less.

It seems like every time I fuel-up I nearly Dead-stick within the first circuit or two. I have Dead-sticked once after fueling. The engine runs erratically and nearly dies; and after a few minutes, the problem goes away.

Am I over-filling the tank? I like to fly inverted and I do aileron rolls and loops and stuff, but that does not seem to cause a problem with the engine because I usually wait until it's running fairly reliably before I try that stuff.

One more thing....It runs GREAT on the ground and I tend to run about one to two clicks rich because I don't need the speed as much as I need the engine, (and I have been told that it leans-out a bit in the air).

Any help would be worth every penny I paid for it....

bkdavy

My Feedback: (1)

First of all, why not refuel before every take off? I never start a flight without a full tank. That way, I always know how much fuel there is at the beginning. Use a kitchen time if you don't have one on your radio. Run a full tank through the plane and time it, then use that as your guide for how long you can fly.

Second, your engine problem could be caused by several things. Since you say it happens within the first couple circuits, then improves, try this. After you start the engine, leave the glow igniter connected, then run the engine up to full throttle for 5-10 seconds. Throttle down to idle, then remove the glow igniter. This will ensure the engine and glow plug are both up to operating temperature, as well as ensure that any fuel thay may have built up in the muffler is cleared out. Depending on how you refuel, you may be putting some fuel in the exhaust side. After you take off, this fuel may be getting sucked back into the engine and causing an overly rich condition for a few seconds.

Third, get your hands on a tachometer. They may seem expensive at first, but they're worth every penny when it comes to engine reliability. Use the tach, not your ear, to determine peak rpm, and then richen it 200-300 rpm below peak. 1 or 2 clicks may not be enough to prevent a lean run during take off. Your problem could be the plane is too lean on take off causing the engine to get hot during your take off run. ABN/ABC engines get looser as they heat up. If the engine is too lean, the increased temperature will cause a loss of compression, and may cause the behavior your seeing. After the engine cools off with the extra air flow and reduced throttle, it runs properly.

Finally, learn how to tune the low end. Its not rocket science, and I'm not going to repeat it hear. Its been posted thousands of times. You could be experiencing a problem with the low end being slightly off. Its worth checking.

Good Luck,
Brad

Dr1Driver

Good advice, bkdavy. I'll add to check the position of the fuel tank. It might be too high. I also agree, refuel before every flight. There are 5 useless things to a pilot:
1. Runway behind you
2. Air speed you don't have
3. Altitude above you
4. A second ago
5. FUEL IN THE CAN ON THE GROUND

Dr.1

flyranger

I fly electric now, but 15 years ago I was flying glow. I had the same problem, after a few minutes of flight my engine quit and I had to dead stick. I destroyed a Great Planes PT-40 into the side of a building like that!! Engine run up ok, break in ok, fuel qualilty ok....what could be the matter. It was VIBRATION! The motor mount epoxy to the fuse rails did not adhear properly causing the motor mount to vibrate too much and creating a bubble in the fuel line. As soon as the bubble got to the carb, no more engine!! Re-glued and remounted motor and was great after that.

derek533

I have the same problem running my Twist with an Evo 46. Here' what I did. Start up the motor and get a good smooth idle going. Then take the plane and physically hold onto it with the nose pointed towards the sky and the nose above your head. Have someone else hold your transmitter for you. Have that person give full throttle and see what happens. If it sputters or hesitates, you need to richen it up some. It may be rich on the ground but when you get it in the air, it will run like a champ. For me, once I tuned the high speed needle utilizing this method, it totally cleared up my problems that I was having (which are real similar to yours).

2slow2matter

My Feedback: (1)

When adjusting low ends, I always assume the opposite. If it sputters, and hesitates, I lean the low end some and it usually straightens right up. If you go full throttle and it suddenly dies, then it's too lean--richen it up some. It sounds like your engine is loading up a bit on the low end.

ashley95

some of the useless things in aviation are runway behind you, altitude above you, and fuel in the fuel bottle.
id refuel after every flight. somone else may have an emergency keeping you airborne longer than you expected to be. and you'll dead stick at the worse time.

carrellh

You must have a HUGE fuel tank in the plane if you are getting two or three flights out of a single fill-up. From what I've been told, and seen at the field, most people put in a tank that will give 10 to 12 minutes of engine run time at full throttle; andfill up for every flight. If you do have an oversized tank, it could be part of the problem.