Campgems
Posts: 1281
Joined: 2/18/2006 From: Arroyo Grande,
CA, USA Status: offline
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quote:
ORIGINAL: MetallicaJunkie quote:
ORIGINAL: blw The low speed needle valve is set too rich. I have a feeling it is..... i have it set flush like the directions say.. ill give it a try tonight when i get home There is more than just low idle speed to consider. You want the enging to pull at its maximum performance, idle at a reasonably slow speed and make the transistion betwee the extreemes without stumbling or quiting. Adjust the high end for maximum RPM less about 400 rpm to the rich side depending on the conditioning of the engine. Fully broken in you can get away with 300 rpm rich but with a new engine, I would go around 600 rpms rich. Then you adjsut the idle . Set the throttle as slow as the engine will run without stalling and then at this throttle setting lean the idle to achieve maximum RPM. Go back and adjsut the high end again. Go back and adjust the idle again. This thime the idle should be much slower. The work on the transistion. Run the engine up after it is warmed up and hold it at full throttel for a few seconds to clear out any loading. Go to full idle and let it run there for a count of 20 to 30, the punch it full throttle. It should jump to the throttle. If it dies as soon as you punch it, the idle is set to lean, open it up 1/16 turn at a time until it jumps to life. If it stumbles and snort before increasing RPM, it is to rich and again adjust, this time to the lean side, 1/16 turn at a time until it jumps. Go back over the whole sequence one more time and then don't screw with the jets unless there is a big change in temp, humidity, or a new fuel mix. You just have to have a tach to do this. Once you have adjusted an individual engine a number of times, you will be able to hear that engines and determine what needs to be done. Untill you get to know the engine though a tach is necessary. As soon as a tweek at the field doesn't work like you thought it should, start from step one, otherwise you are going to meander further and further from the proper setup. The previous suggestion of a 2000 rpm idle is a good target. A couple of our guys with big birds use an air brake setup to slow down the plane after landing. You might look into setting up someting like this on your transmitter after you get the idle taimed. Don
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