Adjusting carb on a Norvel .074
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Adjusting carb on a Norvel .074
For those like me who have not learned how to adjust this carb.......
In the past week I have advanced from not having a clue... to adjusting the carb and getting a good idle and transition. One problem I had last week was too much fuel line to the carb. (I'm using a fueler connection) Making the lines as short as possible helped it to start easily and not lose the prime in the fuel line. The next revelation was finding the starting point to set the needle. I found by trial and error that it was exactly 2 turns from closed. The engines starts every time, hot or cold now. Before, I was starting at 2 1/4 turns. A world away from the right place. The engine would start, run rich and die no matter what I did to the needle. Then I would have to try everything I knew to get it to start again. If it started I just didn't let it idle down very much.
I have found that the engine will go from rich to just right with ONE CLICK of the needle from the starting setting of two turns. If you are very much off to start with, it is almost impossible to find the right setting or even start the engine. Now I just let the engine warm up then let it idle for a time, then advance the throttle and listen to see if sounds rich or hesitates. If it is, make a one click adjustment and let it idle again.
Instead of spending 30minutes trying to start the engine and keep it running today, it only took a few minutes.
In the past week I have advanced from not having a clue... to adjusting the carb and getting a good idle and transition. One problem I had last week was too much fuel line to the carb. (I'm using a fueler connection) Making the lines as short as possible helped it to start easily and not lose the prime in the fuel line. The next revelation was finding the starting point to set the needle. I found by trial and error that it was exactly 2 turns from closed. The engines starts every time, hot or cold now. Before, I was starting at 2 1/4 turns. A world away from the right place. The engine would start, run rich and die no matter what I did to the needle. Then I would have to try everything I knew to get it to start again. If it started I just didn't let it idle down very much.
I have found that the engine will go from rich to just right with ONE CLICK of the needle from the starting setting of two turns. If you are very much off to start with, it is almost impossible to find the right setting or even start the engine. Now I just let the engine warm up then let it idle for a time, then advance the throttle and listen to see if sounds rich or hesitates. If it is, make a one click adjustment and let it idle again.
Instead of spending 30minutes trying to start the engine and keep it running today, it only took a few minutes.
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RE: Adjusting carb on a Norvel .074
It must be the fuel.
I have seen Dickeybird adjust the carb on his cornbread plane (.061)and he said he had just turned the needle one click.
I have seen Dickeybird adjust the carb on his cornbread plane (.061)and he said he had just turned the needle one click.
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RE: Adjusting carb on a Norvel .074
I agree with flyinrog, my .074 is no where that sensitive. I haven't set the needle valve all season long! All I do is fuel her up, open the throttle wide, place my finger over the carb to draw in some fuel with a few flips of the prop, then hit it with my starter. Purrrrrrrrrr I am using 15% fuel and a tornado 6x3, if that helps. It takes about a 1/2 turn or more of the needle valve to get my engine out of tune. Sounds like a leak in the fuel tubing to me. I would check all the fuel lines from the tank to the engine.
Hec
Hec
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RE: Adjusting carb on a Norvel .074
I was just happy to find a place where the engine would crank more than once.
If the setting was very far off, then I couldn't get it to restart. Two turns is the magic spot with the fuel I'm using.
If the setting was very far off, then I couldn't get it to restart. Two turns is the magic spot with the fuel I'm using.
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RE: Adjusting carb on a Norvel .074
I have been using 25% nitro, which does make a big difference in setting up the needle, making it less sensitive. By filing off some material from the arm where it contacts the concentric scew head used as a stop, you can get it to idle even lower.
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RE: Adjusting carb on a Norvel .074
How many times do you think it's user error. Let me correct myself, I intended to use Norvel 25%. I altually mistakenly used Cool Power 15% because I was bench running an OS .46 LA the day before. Now that I have the right fuel the AME .061 is much more adjustable. One fuel is green and the other is red but my sight isn't going out yet so it must be simple stupidity. At least it was a good test.
#14
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RE: Adjusting carb on a Norvel .074
I'm still using Byron's 1/2 A fuel (25% nitro) with some added castor to give 20% oil.
(I'm not a proponent of extra oil content, and some friends have constant engine problems which I attribute to their dumping extra oil in their fuel.)
Good luck,
Dave Olson
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RE: Adjusting carb on a Norvel .074
Japanman: I know the Norvels take more amps to get a good glow, so I dial up my power panel into the red (4amps) a cox will glow at 3. But I have never taken the head off to take a look at this one.
Scar: I use a online calculator at this site to add castor. The engine seems to run better with the 20% oil than 16%. It locked up a few times with the straight 16% when it was new.
http://www.nitrorc.com/
click: Fuel Blending Workshop, then click Add Oil Only
Scar: I use a online calculator at this site to add castor. The engine seems to run better with the 20% oil than 16%. It locked up a few times with the straight 16% when it was new.
http://www.nitrorc.com/
click: Fuel Blending Workshop, then click Add Oil Only