neuroza

Hi, I have one question... On the ground I adjust the needle just perfect and the engine go really smooth and everything seems ok.
So when I try to take of, when the plane gain some speed, just to take of, the engine die...
What can I do???

Thanks!

krayzc-RCU

My Feedback: (31)

richen the low speed needle its inside the throttle barrel on most use a flat head screw driver

Kmot

My Feedback: (24)

Try pointing the nose of the airplane straight up while holding it on the ground. Then see if the engine dies. If it does, try enrichening the neddle slightly to prevent the engine from leaning out when the nose is pointed up.

Campgems

Kmot has it right. It sounds like you are going lean as the engine gains RPM which it will do as the plane is gaining speed. I usually set for maximum RPM and then back off to the rich side by 400 rpm. If I try to run leaner than that, the engine will die, sometime a minute or two into the flight as it heats up.

Don

neuroza

I have a air bleed carburetor.
I try to put nose up adjustment and my engine when I put the nose up slightly increase in speed.
The hi speed needle is set to go on maximun RPM on the ground...

When I put the needle to optimum do I need to close it or open a little bit for flying???

Thanks!

krayzc-RCU

My Feedback: (31)

neuroza
let say u can acheive 10200 on the ground with the high end. Richen your high needle up to drop the RPM to 10,000 then make sure u have a good transition from low to high. (open the high to drop those 200 RPM's)

neuroza

OK krayzc-RCU.
I don't have the meter for RPM, so how much (approximately) do I have to open the Hi needle when is optimum on the ground???

Thanks!

Turk1

Try to open about 3 clicks from max.RPM s.

neuroza

Ok, thanks!

greyfoxx

Neuroza, a couple of other things to consider beyond the low end needle valve settings is, how far from the carb is the clunk in your fuel tank, and check the position to assure that the tank is not mounted lower than the carb. Another thing is to pressure/vacuum test your fuel lines from the clunk to the carb. I had basically the same problem with an OS 160 last year and it drove me absolutely out of my head, check and double checking everything more than once. Seeing as how I had new tubing throughout the set up, I never considered that there might be a fuel line leak. Yep, found a pin hole in the fuel line between the needle valve and the carb, problem solved. It was fine on the ground and with the engine run up with the nose held straight up, but 50 feet in air and it would go lean every time. Also, if your engine is larger than a .75 (two stroke glow) go to the large tubing as well.

Unfortunately, I have found that "Experience is a hard teacher. She always gives the test first and the lesson some time later!"

Phillip

Quikturn

My Feedback: (12)

Hi neuroza, What you describe sounds exactly like what I was experiencing 2 years ago on my Midstar 40 with a Tower Hobbies 46 engine. It would start and run fine on the ground and would die at takeoff or in flight. A fellow modeler suggested replacing the glow plug with a new one. I did and haven't had a problem since.