aps f4u

forgot to mention that all i did was put new o'rings in them,and they run fine,with no problems.

Phlip

Sorry, Ken

I must admit I lose focus on these threads that go on and on with suggestions being offered. I'm a troubleshooter (machine tools) to support my airplane addiction, so I have to take a very logical approach to these things ... and I'm not insinuating that you haven't taken a logical approach in what you've done so far.

BUT ... I have a few questions for which I haven't seen the answers yet. Maybe that would help.

1. You say you've had three engines in the plane. Did it fly OK with them, or did you experience the same problem?

2. Have you used the same radio in any other planes? Even though you don't have metal pushrods, perhaps there is a problem with the receiver cutting out the throttle servo when the signal gets weak.

3. You said the engine runs fine on a test stand and (I think) in the plane on the ground. When the motor is in the plane, does nose up/nose down, upright/inverted effect it at all?

4. Does the engine throttle OK? Is the throttle wide open, half, or idle when the engine quits?

With the answers to these questions it would be much easier to try to zone in on the problem. Again, perhaps the answers are here, but I haven't found them. Perhaps I'm confused by other's assumptions.

Phil

KENB85

PHILIP-- HEY MAN - I'M IN MACHINE TOOLS TOO - I DESIGNED TOOLS FOR DELTA THE LAST 20 YEARS I WAS WORKING. NOW THAT I'M RETIRED, I'VE FOUND SOMETHING THAT TAKES UP ALL MY TIME.

1-YES - THAT WAS THE POINT I WAS TRYING TO MAKE - ALL 3 ENGINES DIE - THEY RAN FINE IN OTHER PLANES, IN MY ENGINE STAND & IN THE PLANE ON THE GROUND - I'VE RUN SEVERAL TANKS OF FUEL THRU THEM - THE PLANE FLIES GREAT WITH ANY ENGINE TIL IT DIES.
2-IT'S A COMPUTER RADIO AND I HAVE 4 PLANES IN MEMORY - THE OTHER PLANES WORK GREAT -- I HAVEN'T TRIED SWAPING OUT THE RECEIVER AND SERVO - BUT IT WORKS FINE ON THE GROUND - THE RADIO CHECKS OUT FINE IN A RANGE CHECK.
3-SO FAR IT HASN'T DIED WHILE IT WAS INVERTED BUT I HAVEN'T FLOWN INVERTED FOR EXTENDED PERIODS.
4-THE ENGINE IDLES GOOD - ACCELERATES GREAT - I CHECKED IT WITH A TACH BUT IT'S BEEN A WHILE - I THINK IT PULLED AROUND 11,000 WITH NO PROBLEM - IT SEEMS TO ME THAT MOST (OR ALL) THE TIMES IT HAS DIED, I WAS FLYING LEVEL AND THE THROTTLE WAS CUT BACK SOME. I DON'T THINK IT HAS DIED WHILE AT FULL THROTTLE BUT ON THE TEST STAND IT RUNS GREAT AT HALF THROTTLE.
WOULD THERE BE SOMETHING ABOUT THE SHAPE OF THE TIGER II THAT JUST KNOCKS THE AIR OFF THE CARB. INLET AT CERTAIN SPEEDS? I'VE HAD OTHER PLANES SHAPED SIMILARLY AND THEY RAN FINE. THE CARB. ONLY HAS THE PROP & SPINNER IN FRONT OF IT.

THANKS GUYS - FOR STICKING WITH THIS ONE. I'M SURE IT'S SOME MINOR, SILLY LITTLE THING THAT I SIMPLY HAVEN'T THOUGHT ABOUT OF JUST OVERLOOKED.


KEN

Phlip

That's one thing I thought about ... really

I'd try 2 things now.

1. Try a different receiver.

2. Take off the spinner.

Good luck!

Phil

KENB85

I'LL TRY THOSE THINGS AND THE ONBOARD GLOW IGNIGHTER AS SOON AS IT WARMS UP A LITTLE - QUITS RAINING AND THE WIND SLOWS DOWN SOME - IT'S BEEN ROUGH IN GA. FOR A WHILE -- OK - OK- DON'T YOU YANKEE BOYS HAVE A HEART ATTACK LAUGHING - IT ONLY GOT UP TO 45 DEGREES HERE TODAY.

KEN

jettstarblue

Crappy fuel. You didn't mention whether you tried a different/new fuel.

Jetts

KENB85

OH, BUT I DID MENTION IT -- SEE POST 10 - SEVERAL DIFFERENT JUGS. BUT I'VE ONLY TRIED 15%. DOES SOME OTHER MIXTURE BURN EASIER?

KEN

Live Wire

The way I read this was 2 motors ran OK on the plane and one didn't SORRY. Air flow over spinner , go with smaller spinner or take it off and try it. A air cleaner on the carb will work . Turbulance from spinner or propwash will cause this if the cowl is closed under motor restricting air flow to carb in flight!!

KENB85

I LIKE THE AIR CLEANER. IT'LL BE HARD TO USE A SMALLER SPINNER - MAYBE I'LL TRY A PROP NUT. -
FOR THE RECORD - ALL MOTORS DIE AFTER A COUPLE OF MINUTES FLYING - ALL MOTORS WORK GREAT ON OTHER PLANES & ON TEST STAND & ON THIS PLANE UNTIL IT'S IN THE AIR.
---ANYONE NEW TO THIS THREAD - FOR THE WHOLE STORY, CHECK POSTS 1,9,10,12,13,15,20,22,28,30 & 32 -- YOU KNOW, I SHOULD HAVE WRITTEN A BOOK.
HEY - IF IT WAS EASY, ANYBODY COULD DO IT AND IT WOULDN'T BE A CHALLENGE.

KEN

Live Wire

It surely is not the radio unless you have one with the failsafe and you would not need the answers. What happens is a vacum over carb instead of pressure, like mounting an engie in a cowl with out vents! Good luck.

jettstarblue

O.K. O.K. please STOP YELLING!!!!!!

Jetts

Kaos Rulz

Ken,

The on board glow igniter will just be more weight and something else to fool with that you don't need.

Having read all your posts, this smacks of a pin hole in the fuel delivery line inside the tank. Now I know from your post # 9 that you replaced all plumbing and tank, however, this problem has to be with the plane's tank, or plumbing, because the symptoms duplicate with various engines. I suspect you have a pin hole inside the tank's fuel delivery line. It is probably low enough to allow the engine to run OK until the fuel level drops below the hole at which point it thens sucks air and causes a lean run causing the engine to stop running.

If you haven't already done so, fill the tank 1/4 full and run engine on the plane checking for lean running indicators. (ie. nose up, varying throttle settings, etc...)

I sure hope this helps, because I know how frustrating a cantankerous engine can be.

DBCherry

My Feedback: (4)

And yes Ken, please stop YELLING.

KENB85

--ED -- I THINK YOU'RE RIGHT. I REALLY BELIEVE IT'S SOMETHING IN THE FUEL SYSTEM. BUT- I'VE TOTALLY REPLACED THE ENTIRE SYSTEM 2 TIMES AND ON 3 OR 4 OR 5 OCCASIONS I'VE REPLACED A LARGE % OF IT.INCLUDING THE PARTS INSIDE THE TANK. RIGHT NOW I TRYING A FILTER WITH A WEIGHT ON IT THAT I'M USING FOR THE CLUNK. THE TANK IS TOTALLY CUSHIONED IN 3 DIFFERENT FIRMNESS FOAM PADS. WHEN I'M RUNNING THE ENGINE IN THE PLANE ON MY STAND, IT WILL COMPLETELY EMPTY THE TANK BEFORE DIEING. I JUST HATE TO GO ON BEATING A DEAD HORSE, HE'S NOT GOING TO GET UP AND GO ANY MORE. I'VE ALREADY BOUGHT A 'RAM 50' GLOW STARTER SO I MIGHT AS WELL TRY IT (WHEN I GET ALL THE PARTS). EVEN THOUGH THEIR ADD ON THEIR WEB SITE SAID 'COMPLETE, NOTHING ELSE TO BUY', WHEN I GOT IT I FOUND OUT I STILL NEEDED AN AMPLIFIER, A CHARGER, A 'Y' HARNESS AND A CHARGING JACK.

--JETTS & DBCHERRY -- WHAT CAN I SAY? PLEASE GO BACK AND READ POST 20 AGAIN (THE LAST PARAGRAPH) - IT'S NOT LIKELY THAT I'M GOING TO STOP USING ALL CAPS & I WISH THAT EVERYONE ELSE WOULD BE COURTEOUS AND START USING ALL CAPS FOR US HALF BLIND OLD COOTS WHO DON'T HAVE FINGERS. IF YOU JUST CAN'T MAKE YOURSELF DO THAT - THEN HOW ABOUT DOUBLING THE SIZE OF YOUR LOWER CASE.

I'VE GOT IT. -- FROM NOW ON I'LL PUT A NOTICE AT THE BEGINNING OF ALL MY E-MAILS----'NOTICE; IF YOU'RE SENSITIVE AND CAN'T BEAR TO LOOK AT ALL CAPS, PLEASE DON'T READ THIS'.

KEN

Kaos Rulz

Ken - I sure hope you find this elusive culprit. Please let us know when you do.

KENB85

ELUSIVE CULPRIT? MAYBE THERE'S A GRIMLIN HIDING IN THERE SOMEWHERE AND WHENEVER HE WANTS TO, HE PINCHES THE FUEL LINE. THEN HE HIDES AGAIN. I MIGHT FALL BACK ON THE IDEA IN POST 22 ABOUT A SMALL AMOUNT OF HIGH EXPLOSIVE. THAT SHOULD TAKE CARE OF IT.

KEN

P.S. - SORRY GUYS, I FORGOT --- 'IF YOU'RE SENSITIVE AND CAN'T BEAR TO LOOK AT ALL CAPS, PLEASE DON'T READ THIS'.

hnesitd1

I had a similar problem with an ASP 46. The symptoms were that the engine would start and I was able to lean it out with no problem -redlined at about 12,000 RPM. Once the aircraft was in the air, the engine, after several minutes, would begin to lose rpm and at some point, stop. I did all the normal fault finding things, looking for air leaks, changing glow plug, etc - no cure! I was convinced that the problem was associated with fuel supply and with this reasoning raised the tank - no cure! However, (on the bench) when I lowered the tank until the spray bar was positioned a good inch above the 1/2 level of the tank, the problem disappeared! This is what I think was happening. I believe that there was a design flaw with the carbs and that in a very short time (even with the engine in a screaming 2 cycle) the mixture went rich and started to cool the glow plug - resulting in missing and a drop in engine RPM. Anyway, with the tank positioned substantially below what is considered optimum, the engines(s) (there were (2) of them) performed well. With the tank high fuel has what is called a, "head", on it. In other words, depending on the high speed idle adjust, gravity and siphon plays a part with respect to the fuel supply to the engine.

KENB85

I'VE RAISED AND LOWERED THE TANK - SEE POST #1 - BUT I DON'T THINK I'VE GONE A FULL INCH IN EITHER DIRECTION. WHAT HAPPENS WHEN YOU'RE DIVING OR CLIMBING AND THE ENTIRE TANK IS ABOVE OR BELOW THE ENGINE?

KEN

delman

While helping someone at the field one day I found that his fuel tank hatch on his Tiger 2 was pinching/kinking the fuel pressure tubing causing his engine problems. Also you might check that the fuel tank pressure hole is open on the tank from the muffler. Hope this helps.[8D]

hnesitd1

The symptoms I experienced were with the engine mounted on the test bench with the spray bar positioned in the, so-called, ideal position, ie, spray bar 1/2 of the mid tank position - similar to the way it was mounted in the aircraft. Only by lowering the tank on the bench first was I able to eliminate the problem. At first, I raised the tank - this made the problem appear earlier during the engine run period.

jettstarblue

I'VE FOUND THERE IS ONLY ONE CURE FOR THIS TYPE OF PROBLEM-
STICK OF DYNAMITE.

Jetts

KENB85

WOW, MAN - I CAN READ THIS ONE.
JETTS -- I'M LEANING IN THAT DIRECTION-- BUT IT'S A BEAUTIFUL PLANE AND FLIES GREAT (AS LONG AS THE ENGINE RUNS.)

TELL ME - HOW DID YOU GET THE LARGE BLUE LETTERS TO WORK? MY BOLD, ITALICS & UNDERLINE BUTTONS DON'T SEEM TO WORK. NEITHER DO MY FONT FACE & FONT SIZE BUTTONS.
I CAN EASILY READ YOUR MESSAGE. IT'S GREAT.
ALSO -- DOES ANYBODY KNOW HOW TO GET THE RIGHT TIME TO SHOW ON THESE MESSAGES. THE ONE I JUST GOT FROM JETTS SHOWS THE TIME AS 4:12 PM TODAY. I GUESSING THAT SINCE NOW IT'S ONLY 1:29 PM -- THERE MIGHT BE A MISTAKE.

KEN

FHHuber

Has anyone mentioned:::: Pinhole in the klunk line :::: yet?

Sounds like a classic case of it.

rctrax

I think you would be well advised to go back to the glow plug.I have had them go bad even they appeared to work t They would start it up fine and run ok on the ground but as soon as I tried to take off they would lose power and/or quit. The element gets coated with cooked oil and lose thier ability to glow with the catalitic action with the fuel needed to sustain combustion. A new plug is the standard fix in these cases. I tried a new one and my problem went away.

themanimal

My Feedback: (1)

sounds like a fun plane. I had an mds with a similar problem, what worked for me was a home made- "one way fuel reservoir" that I built with a hyperdermic needle body, a screw, some tubing and silicone. It prevents the engine from being robbed of fuel during extreme manuvers or when the pick up finds a pocket of air.

Here is how you build it. pretty simple. Trow out the needle plunger and take the needle off. Cut the body of the syringe to about 1/ 12" (from the needle end) take a 2" piece of tubing and cut 2 slits in the side of it about 1" long each and then put a small screw into the end of the tubing. Take this piece of tubing, put it into the syringe body (with the slits and screw inside) and seal it shut with silicone. now connect the line to the engine where the needle used to go and connect the siliconed tubing end to the fuel tank.

When the plane is running the slits expand, fills up the syringe with fuel and supplies the engine with fuel. if there is a pressure drop the slits close and the fuel pressure remains high enough to run the motor.

If that doesn't work, I suggest the dynamite. Lighter fluid and a match will also get the right response.

Cheers. And yeah (STOP YELLING AT EVERBODY--ITS HARD TO READ)