TRM231 - adjustment problems or to much oil?

[Helihover]

Hello

I have a spectra-G with the TRM-engine in it. Yesterday I had a whole day at the field and was flying my gasser.

I do, however have some problems with it. In hover it kicks its tail a lot and quite violently, also I have oil coming out of the muffler after each flight.

Needles are approx 1,5 turns out, and have tried to lean the low needle. What happends if lean it is that the engine is racing in idle (going up and down i revs) - turning it out (richening) leaves me with a constand idle but as soon as I land the engine quits. Throttle pick up is good in either scenario.

The plug is very dark brown after flight. Currently I am hovering it as I am afriad that the engine will quit in flight as it is clearly not running at its optimum.

In hover the rotor-head spins at 1500 rpm, I am using stock air filter and Zimmerman exhaust and ready made fuel (camper) with 2 percent syntetic oil. The engine has about 10 liters of fuel thru it to this date.

Any inputs would be highly apprechiated.

Thanks, and best regards

[bigrcr]

Some oil out of the muffler is not a big deal unless it is excessive which is a symptom of overloading with oil. A very dark plug is suggesting either too much oil OR needles that aren't set correctly..yet..

Clean your plug or replace it.

Make sure that the motor is not idling off of the "needles only" (this will cause you to chase the settings)and is idling at a throttle setting. Make sure that the butterfly in the carb is being held at approximately 1.5 to 2mm of its seated position. The stock idle set screw is good for this.

Start the motor and then adjust (very slowly) the low needle so that it is not racy (turned in), and not too "burbly" (turned out). You don't need to have a smooth idle and in most cases do not want the idle too smooth as it should be slightly to the rich side (too smooth can quickly get lean when heated up). You will most likely find that the low needle is happiest at 1 1/4 to 1 3/8 open, but this is somewhat dependant on the area and climate you fly.

Hover the model and get a feel for the needle settings. If it transitions as well as you say, then go fly around and slowly load the model and sense how the high needle setting is reposponding. If it loads and bogs excessively, land and lean it a little at a time until this gets better. If it does not load and bog, richen the high needle a very small amount and try again. Continue to do this until it does load and bog, then land and go back to the last good setting.

Once this is done, fly out the flight and land. Once the motor has fully cooled, fuel up, start it up and affirm that the low needle is still the same slightly lumpy setting as it was before (using the same throttle opening).

Several things can make the model kick around in flight and in hover, not all are motor related. Sense if the motor is causing this by listening to what it is doing and see if the kick or erratic movement is assocaited with what you sense from the motor.

Hope this helps!

BIGRCR-John Garst

[Paulus]

Hi,

I have also a TRM231and just started the breaking-in. In the break-in procedure there is written to use a needle setting not lower than 1 3/8 turn. I just read in this topic that the needle could also work at a 1 1/4 setting? What is correct?

Regards, Paul

[PaulH]

In case you haven't already seen, there is a gasser tuning FAQ sticky one level up in the forum: https://www.helifreak.com/showthread.php?t=17410 It may not answer all of your questions, but it should at least get you started.

[Xcellgasman101]

If I'm not mistaken,, the Spectra G hovers on the High needle doesn't it??? Do just what bigrcr said, for the L needle, then put your Spectra into a hover,, listen to it, if it is stumbling then lean (turn in) the H needle about the blade thickness of your screwdriver,, Hover again, Keep doing this until it smoothes out... You should get a small blurb about ever 10 to 15 seconds,, Your go to go.. Hope this helps.. XGM/VGM