Heb ik er nog 1 voor je voor het helpen afstellen:
High needle
low needle covers thru hover.....high needle from above hover to full throttle.
A bog at the onset of throttle is typical of too rich on the high needle.....
A "brownout" of power at the top of a full throttle climbout (after it took the throttle and pulled well at the bottom) is typical of a high needle being too lean.
What if I'm hovering at say 28%?
On a 231, there would be two things, 1, you're to lean on the low needle, or you have differential in your atvs on the throttle which would screw up the timing effect between the engine, and collective movement. Plus give you the wrong throttle position relative to your butterfly inlet. You would have a vibe you can 't get rid of no matter where you put the throttle curve. I say this to help you understand how important setup really is on a gasser...Why? because the torque band is so wide.
How can I understand that last statement?
To see this, consider yourself in a hover at a good rpm on the gasser. Without the throttle moving, just raise the hover pitch, you can raise the hover pitch pretty good before you see a change in rpm...On a glow, it would drop off much sooner. The longer it takes to make a change, the wider the torque band for that amount of throttle. Since the gasser is so strong, the throttle has to be in the right place, at the right time, in order to keep everything in balance for as timing between the throttle, and collective movement to maintain a constant rpm without the vibes..
Adjusting the high needle:
Like I said before those nifty positions 1 3/8 's on both needles took a long time to find, so the hard work is mostly done. The high needle comes into effect about 50 %, it handles the other 40 % of the fuel flow, but I consider it for wide open only...Yes, it can effect the hover, but its best not to look at it that way..Only for wide open throttle is the way I do it for novice. Once you get more experience, you'll learn the little stuff like just tuning from idle, and effecting the hover with the high needle...For now, just do what I tell ya
You can move this needle at 1/8 increment, so that means it not as sensitive....
How do you know you have the high needle to lean?
It will get real smooth, and not climb out as fast, and if you continue, it was just quit, all of a sudden. If you don't know, then always adjust rich first to see if the climb improved. Most 231's near sea level with air filter, and 643 series run 1 3/8's on the low, and 1 1/4 on the high.. With these new engines, I've never run any leaner than 1 1/4 on the high, and no leaner than 1 3/8 on the low..
I haven't touch my needles on the 231 since I first adjusted them.
3. What should I be listening for from the engine?
When first starting the engine, you want to hear a steady idle, but, your not going to get it till it warms up, so just add trim till it does., let the engine warm up a little before you take off.
When you go to 1/4 throttle, its should kind of miss a little from being rich but reach operating rpm fairly easy, and stabilize (this is without a gov)
It will have a Evenrude sound to 1/4 throttle From 1/4 throttle to half, it will have a low tone, and pretty well be trying to clear out. Once you get to hover, if you hear a slight hesitancy miss, but see it in the tail wagging slow, back, and forth. That will be a sign that your fat in the hover. Dont be so quick to run and lean it, this is a good thing on a gasser, you just minimize it ..If it goes away after your warmed up, then your on the money...I let mine pulse the tail, about once every 10 seconds to let me know I'm rich, when I'm flying real hard
Don't worry about engine temps so much. So long as you run a good rpm, and the suggested needle settings, you'll do fine...I don't even check temps now. If its to lean in a hover, you'll see it vibrating, and sounding real raspy, and get real smelly..
Succes!
Eric.