ORIGINAL: Jarrah
Ok so i went to the field yesterday to see if i had fixed my problem. Nope the darn thing is still cutting me out and it is really annoying me, it sits there at idle for a few mins fine, taxis out fine then as soon as im on the strip and give it full power to take off bam the motor goes to die, u can save it by backing the throttle off to idle right away. Also i have had a few very low level dead sticks into long grass because of this which is annoying. If a few of us are having this problem it leads me to believe there maybe a problem with some of these motors. I have tried all low and high speed needle settings to no avail!!
Yup it's not tuned up properly. I've been through all of this on my PTS and .46's... all of which are running reliably now.
Make sure that:
- You do not have a cut or nicked tube anywhere. This can often hide from you.
- You perform ALL tuning with only 1/3 of a tank in the plane
- You remove the limiter pin so that you can turn the needles past the stop
- You do something about the infamous "needle walk" on the Evolution engines.
Needle walk: Once warm the needles tend to "walk" with engine vibration. A little locktite and tightening of the clip helps a lot.
As you throttle up note HOW the motor tends to die. This will help you pinpoint the problem.
Does it get sluggish, then slows and dies?
Or does it die almost immediately as if you threw a switch to stop the engine?
The former means that the engine is too rich, the later too lean.
The low speed needle setting affects the engine through most of the throttle range, so if it dies or goes sluggish and then dies, before it every gets to full throttle at high revs, the low speed is off.
Run the plane up to about 70% throttle with 1/3 of a tank, then do the pinch test.
Nose the plane up in the air, and make sure that it does not die (it will speed up as it leans out).... then nose down and make sure it does not die (it will slow down as it richens out)....
If you can get this somewhat reliable, take it back to idle and try gunning the engine back up to 70% several times to observe the behaviour. Does it cut out?
If not move to the same tests at full throttle.