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Old 09-29-2014, 02:11 PM
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thought you were talking about a 150? - 27x10..... on a 120 i presume you are talking, sounds too small, either 27x12 or better a 28x10 will load it better
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Old 09-29-2014, 02:19 PM
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Originally Posted by Low_Cal View Post
I'm using a 27x10 wood. I think I have a 27x12 I could try to see if that loads it up better, but I wouldn't expect that to be the optimum prop for 3d on a 31 lb plane.

The needles are set according to the manulal, and it runs at average CHT of 270*F. I can close the LS needle just a hair more cleaning up the midrange pretty good, but then I start getting a deadstick now and then, which can be bad if it happens at just the wrong time. So I just let it run rich through the midrange, and change plugs often.
Let the engine idle after starting to warm it up. Then quickly advance the throttle to high. If it dies that means it is lean on the bottom end so richen the LS needle about the width of a flat blade screw driver (approx. 1/32"). Start the engine and repeat the test until it doesn't die or stumble when going from low to high speed. Then let the engine run wide open for 10-20 sec. If it sags then open the HS needle up just a tad. Repeat the low to high test and adjust as necessary to get a smooth transition. Shut the engine off, fill the gas tank then after a few minutes, start it, check the low to high transition and if reasonable close go fly! Get your thumbs comfortable then do a long sustained vertical upline. If the engine sags the HS is a bit too lean so land and open it up a bit. If the engine won't idle down upon landing richen the LS needle a bit.

Do the whole process again until everything is how you like it. Be patient as many of us have taken all afternoon to get the needles like we like 'em. It is time well spent.

Good luck. Let us know how it works out.
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Old 09-29-2014, 02:26 PM
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Originally Posted by clivem View Post
thought you were talking about a 150? - 27x10..... on a 120 i presume you are talking, sounds too small, either 27x12 or better a 28x10 will load it better
Whoops, that was a typo! Its a 32x10. I used to have a DA-100, so I still have those other prop sizes in my mind.
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Old 09-29-2014, 02:33 PM
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Originally Posted by The Dirt Doctor View Post
Let the engine idle after starting to warm it up. Then quickly advance the throttle to high. If it dies that means it is lean on the bottom end so richen the LS needle about the width of a flat blade screw driver (approx. 1/32"). Start the engine and repeat the test until it doesn't die or stumble when going from low to high speed. Then let the engine run wide open for 10-20 sec. If it sags then open the HS needle up just a tad. Repeat the low to high test and adjust as necessary to get a smooth transition. Shut the engine off, fill the gas tank then after a few minutes, start it, check the low to high transition and if reasonable close go fly! Get your thumbs comfortable then do a long sustained vertical upline. If the engine sags the HS is a bit too lean so land and open it up a bit. If the engine won't idle down upon landing richen the LS needle a bit.

Do the whole process again until everything is how you like it. Be patient as many of us have taken all afternoon to get the needles like we like 'em. It is time well spent.

Good luck. Let us know how it works out.
Yeah, that's the procedure I used to tune it, though I've never had all afternoon to repeat it over and over! Guess I could schedule some time and try that. It transitions well, does long sustained up lines without saging, runs really well, just sounds rough at part throttle. A lot of extened hovers will make it trip my Spektum 300*F alarm, but if I fly around with some speed for a 30 seconds its right back down to 250*F.
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Old 09-29-2014, 03:49 PM
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They're get'n lower mate.....
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I havent changed a plug in years .......and me 3w is still a ball tearer actually it should be wore out by now with all the flights on it
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Old 09-29-2014, 05:13 PM
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If you have any direct air flow going against the carb, cover it up. There have been several "tuning issues" that were caused by air flow directed to the carb. Also try using a tube on the vent of the carb and running it into the fuse. It may just be a disruptive air flow issue to or around the carb.
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Old 09-29-2014, 05:14 PM
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Also what exhaust are you running? My low end is leaned out as much as possible and my pipes seem to give it a slight low mid range burble in the air.
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Old 09-29-2014, 06:32 PM
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Originally Posted by Low_Cal View Post
This is a new DA-35 and DA-60, and DA recommends Redline from the start. Two years ago, I started flying a new DA-150 on Redline, and the rings still haven't full seated in that motor; beginning to wonder when they finally will. I think I have about six to eight gallons through the DA-150. So I'm thinking about using something like Pennzoil Air Cooled for the break in of these two new engines.
Break in is not a matter of age but rather run time. If the DA150 only has 6-8 gallons through it in two years the "problem" isn't the oil. Get out and burn some gas!
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Old 09-29-2014, 07:02 PM
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Break in is not a matter of age but rather run time. If the DA150 only has 6-8 gallons through it in two years the "problem" isn't the oil. Get out and burn some gas!
I burned that much fuel in the past week prepping for my final IMAC competition.
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Old 09-29-2014, 08:20 PM
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+1 for the cowl pressurization/airflow suggestion. I had some ugly issues with all three DA-120 with midrange burble until I removed the 1/2" lip I intentionally left on the bottom of the cowl to pull air out but it must have been causing a low pressure for the carb. Knocked the lip down to less than an 1/8" and the burble is gone. Prior to removing the lip I put the brass pressure fitting on the carb running a fuel line into the fuselage and plugging the stock breather hole on the plate. Didn't seem to help but I don't intend on taking the tubing off. +1 Running more fuel through the engine as well.
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Old 09-29-2014, 11:48 PM
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Yep I did the static pressure port to carb vent setup from the start; I have a port on both sides of the fuse running through a "T". There is a small opening in the cowl for carb cooling, just the one that came there from 3dhs. I could try blocking that off and see what happens.


I would love to run more fuel through this baby; hopefully I can find the time before Winter hits here.
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Old 09-29-2014, 11:52 PM
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Break in is not a matter of age but rather run time. If the DA150 only has 6-8 gallons through it in two years the "problem" isn't the oil. Get out and burn some gas!
Haha!
How many gallons do you think its going to take with Redline at 40:1 ?
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