dwaynet
Senior Heliman
Location: Fairfax, Virginia
| The low end needle controls between idle and about 55%, the high end covers from about 40% to 100%. There is a spot, as you can see, in the middle where the two needles cross. If you have a reliable idle and the transition to power is smooth then don't touch your low end needle. It is very sensitive and requires very little movement to do alot.
To set the low end:
Let it idle for 10 seconds. Then transition to hovering throttle. If it does not load up with fuel and die then it is probably ok. You can also do this: Pinch the fuel line at the carb while the engine is idling. It should run for about 3 seconds then start to die.
To set the high end:
The smoke you get depends on the fuel you are using, so the best way is temperature and performance. Fly for a minute then check the output bearing to see that it is cool to the touch. The output bearing is the front bearing, closest to the fan. The head will be hot, but you are interested in this front bearing. If it is cool, I will lean the main needle a few clicks and fly for another minute, then recheck. Eventually it will start to get warm, then I go back rich 2-3 clicks from that spot. Fly for a minute and recheck to make sure bearing is cool. You should be set for the rest of the day.
When you first arrive on later days fly your first tank for a minute and check the front bearing. You will probably still be ok and not have to readjust. I hardly ever went more than a click or two leaner or richer until the seasons changed (summer to winter).
There are a multitude of ways to tune an engine, but this works great for me and is the least complex way I know of that works. I see in another post you bought a temp gun. I can't begin to tell you how to use that for this unless you want to set it my way first, getting it right, then read from a predetermined area of the engine and record that temp for future use.
Hope that helps some,
Dwayne |
