rdrude

I am going to post my question here in case no one is active on the TGY 52 thread.
Ok, need some help. Got my 1st gallon through the engine with no problems... matter of fact it ran great. Well, I took off last weekend, and engine died in flight right after takeoff. It has never done that before. Dead sticked it and found that the spark plug came loose. Tightened it up and now I can not get it to go above half throttle without dying. Idle and up to half sitck is just fine. Any ideas? I have adjsted the needles with no luck. What should I look for?
Thanks,
Rob

CK1

My Feedback: (60)

Did the Spark plug come loose from the cylinder , or did the plug wire come loose from the plug???

rdrude

The spark plug came loose from the cylinder. The boot was snug to the plug.

CK1

My Feedback: (60)

The reason I aked about whether the plug or cap came loose is if it were the cap that came loose it would have damaged the ignition module . It is still possible that the ignition is the problem . Have you also tested the Ignition battery ?

rdrude

No, but I have it on the trickle charger now. I will run it up and once the battery is fully charged. If it continues, guess I will order a new ignition module. It appears that the ignition is the primary culprit. Thanks for the info!
Rob

soarrich

My Feedback: (98)

It sounds like you have a plugged "H" circuit. The first thing I'd do is the the "H" needle valve out an squirt some fuel in to try to clean it out. The with the "H" needle still out I'd choke it and flip it some. Reassemble an try it again.

soarrich

My Feedback: (98)

A low battery will cause it to missfire at high rpms.

rdrude

Well, it is not misfiring at high RPM's, it is shutting off at anything above half throttle. Literally, once I go above half throttle the engine dies...

soarrich

My Feedback: (98)

That sounds like the "H" part of the carb.

brewski

Check the plumbing from the carb to the tank. I've had the same experience with the engine dieing above full throttle once. It turned out to be the fuel filter that I bought that stated that it was for gasoline. It kept getting worse as I woked on it because the material in the filter was swelling and closing off fuel supply. I have sincestopped using inline filters and ony use the felt clunk filters like those used in chainsaws. Your problem may be anything restricting fuel supply. Try a new line with a felt filter stuck down in your gas can to eliminate the tank and plumbing in your plane.

Walt and Sage

<span style="color: #0000ff">Hi Rob,
</span>


<span style="font-size: x-small"><span style="color: #3366ff"><span style="font-family: Verdana">I Purchased the 52 for a friend of mine and it has a washer
that goes <span style="color: #ff0000">UNDERthe spark plug to seal and keep it tight...
</span>
His motor runs GREAT for the money...

Only thing missing is a manual that answers question like this..
</span><span style="font-family: Verdana">Walt...</span></span></span></p>

rdrude

I do have a washer for the plug. I replaced the plug when I initially purchased the engine with an NGK... I believe it is the BPM6RF. Motor has run great right out of the box since new. Great idle and transition with very few adjustments.... up until the plug came loose. Now it is shutting off at anything above half throttle. I am going to try removing the H needle and cleaning it out. I do have a felt clunk in the tank, and my fuel jug is filtered as well. It may be that the ignition fried when the plug came loose. This is only my second gas engine, so I am in uncharted territory here. Thanks for all of the replies in helping me to troubleshoot!
Rob

altavillan

My Feedback: (1)

The vibration the loose plug suffered while loose might have harmed the electrode, the gap might have been changed while banging around, or and most possible, the plug wire could have suffered damage from the plug shaking around while loose.
A plug wire exhibits missfire at high rpm when they go bad.
Me thinks you will be buying a new plug and ignition.

soarrich

My Feedback: (98)

I think a way to test if it's the carb, or the ignition would be to:

Start the engine.

Bring it right up to the speed where it dies.
Now back out the "L" needle 1/2 a turn.
Now try to raise the rpms above the max you did before.

If that works you can continue that all he way to full power if you want, but that will prove it's a plugged "H" circuit. If you still can't increase above what you had before then it's a ignition problem.

I know the engine will run to full power on the "L" circuit alone because the first engine I tuned I really screwed up the carb. I had the motor putting out good top end power, but it idled terribly. I decided to start over and found the "L" needle was out 4 1/2 turns and the "H" was out 1/2 turn..

coralcape

My Feedback: (4)

To check the ignition, you can use an electronic timing light. Just make a TDC mark on your prop adaptor. Use a separate 12 v battery for the light, with thenegative hooked to engine ground. Good luck, red

rdrude

Thought I would report back with an update. Charged the ign battery and changed the plug with a new NGK. It runs a "little" better, but still dies a hair above half throttle. I have ordered a new ignition and will give that a shot. Will report back as soon as I receive ignition.
Rob

Tired Old Man

My Feedback: (1)

If you have a sheilded ignition cable, such as one used with a CM-6 type plug, the ignition would not have been damaged by a loose plug. If you have an ignition that uses a rubber boot at the plug with a separate grounding strap it would have been damaged. In that event the hall sensor would have failed and it likely would not run at all.

Look for the problem in the high speed circuit of the carb. Sounds like something got in there blocking the passage to the venturi. When that happes the problem you describe is exactly what happens. Runs fine up to about half throttle then quits as the stick is advanced/opened further.

captinjohn

rcdude, if this is the engine you have....it has shielded ignition. My guess the problem is in the carb like Tired Old Man says.

GreaTOne_65

If I could, I'd would like to add the experience I just had with an engine that had been sitting for about 8 months. I had an episode with another engine, and decided to install the engine that had been sitting with the one that went south. After installing it, I proceeded to fire it up before I put the cowl on. It started right up but would not run above half throttle. Sound familiar?? I went in to my work room, pulled out a new diaphram, fired it back up, and didn't even have to touch the needles. It ran and runs perfectly. I suspect everyone always suspects the worst, some times it is the simple things that get overlooked. I too have had problems with ignitions, but from what he has discribed, I'd be more suspicious of the carburator.

Dale

rdrude

Ok, reporting back again. Replaced the plug and the ignition module. Same thing, above half throttle engine dies. Pulled the H needle and flushed it out. No difference there either. So, do you think I need to do a tear down of the carb? Any other suggestions for me?
Thanks to all for the replies and the help!
Rob

soarrich

My Feedback: (98)

Were you able to richen the low enought to effect the top speed. It should be able to go to top speed or almost top speed just on the "L" circuit, if you do it while it's running.

rdrude

It was turning pretty high RPM's, but I did not tach it. It sure seemed to be at full RPM's, but it sure does not want to go above half throttle.

soarrich

My Feedback: (98)

OK, let's start from the beginning.

Look at the carb, the screw-heads for the throttle plates should both be on the outside, if you can see the threaded part, the shaft with the plate is 180* out.

You put the carb on the engine. The "L" needle is the closest to the engine cylinder?

Walt and Sage

Rob, You might try running it without the felt clunk....

Also if you are using a fule dot into a T line then to the tank and carb, if the end where the
dot plugs in devolopes a hairline crack in it will quite when held at full throttle...
I learned THE HARD WAY on that one....

soarrich

My Feedback: (98)

Anything new on how it's running?