What!! no forum for engine ?'s
12-23-2004 | 07:51 AM
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From: , GA
What!! no forum for engine ?'s
I guess this is a good spot for engine questions. Could someone explain how to tell when to richen and when to lean the low speed needle valve? thanks.
12-23-2004 | 08:08 AM
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From: Gastonia,
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RE: What!! no forum for engine ?'s
12-23-2004 | 08:42 AM
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RE: What!! no forum for engine ?'s
Welcome to RCU!
There are several engine forums. However, since this is a beginner forum, engine tuning is a common topic. Since it's been discussed quite often, I'll suggest that you try some searches for things like "engine tuning". You'll find many useful threads. Following is a short description of what I do to tune the high speed needle on a 2 stroke.
Note, I do all of the following from BEHIND the propeller, and with the glow connecter removed. You should NEVER attempt to make any engine adjustments while you are in front of the prop. Also, these directions assume the engine is fully broken in as appropriate for the engine type, ringed, ABC (or one of the variations), etc.
Start the engine and adjust the needle to be a bit rich. Gradually turn the needle toward lean until the RPMs no longer increase, or decrease a little. This is a sign that it has peaked. You should never fly with the engine at this point, it will lean out in the air and die. Once the engine is at the peak, richen it a bit, perhaps 3-500 RPMs. This provides a good margin for error, and provides extra lubrication for the engine. Once the engine is at this point, hold the plane firmly with two hands, typically one on the fuse near the tail and one wrapped around the leading edge of the wing near the fuselage. When you are sure you have a FIRM grip, point the nose of the plane straight up.
If the engine slows down, it's to lean. Immediately lower the nose, put the plane on the ground and set the needle richer.
If the engine speed does not change, it's just about peaked. You could fly like this, but you risk going lean when your fuel gets lower. It's best to put the plane on the ground and richen it a bit.
If the engine speeds up a bit, keep the nose pointed in the air for 5-10 seconds to confirm it does not slow down. If it holds the speed then it's set pretty well.
If the engine speeds up significantly, you might have set it a bit too far on the rich side, put it down, set it a wee bit leaner and then try pointing the nose up again.
To sum it up, the goal for most sport flying is to have the engine set a little rich. This provides longer engine life, and a cushion against leaning out and having to land dead stick. And, finally, NEVER ADJUST THE ENGINE WHILE YOU ARE IN FRONT OF THE PROP.
Happy holidays...
There are several engine forums. However, since this is a beginner forum, engine tuning is a common topic. Since it's been discussed quite often, I'll suggest that you try some searches for things like "engine tuning". You'll find many useful threads. Following is a short description of what I do to tune the high speed needle on a 2 stroke.
Note, I do all of the following from BEHIND the propeller, and with the glow connecter removed. You should NEVER attempt to make any engine adjustments while you are in front of the prop. Also, these directions assume the engine is fully broken in as appropriate for the engine type, ringed, ABC (or one of the variations), etc.
Start the engine and adjust the needle to be a bit rich. Gradually turn the needle toward lean until the RPMs no longer increase, or decrease a little. This is a sign that it has peaked. You should never fly with the engine at this point, it will lean out in the air and die. Once the engine is at the peak, richen it a bit, perhaps 3-500 RPMs. This provides a good margin for error, and provides extra lubrication for the engine. Once the engine is at this point, hold the plane firmly with two hands, typically one on the fuse near the tail and one wrapped around the leading edge of the wing near the fuselage. When you are sure you have a FIRM grip, point the nose of the plane straight up.
If the engine slows down, it's to lean. Immediately lower the nose, put the plane on the ground and set the needle richer.
If the engine speed does not change, it's just about peaked. You could fly like this, but you risk going lean when your fuel gets lower. It's best to put the plane on the ground and richen it a bit.
If the engine speeds up a bit, keep the nose pointed in the air for 5-10 seconds to confirm it does not slow down. If it holds the speed then it's set pretty well.
If the engine speeds up significantly, you might have set it a bit too far on the rich side, put it down, set it a wee bit leaner and then try pointing the nose up again.
To sum it up, the goal for most sport flying is to have the engine set a little rich. This provides longer engine life, and a cushion against leaning out and having to land dead stick. And, finally, NEVER ADJUST THE ENGINE WHILE YOU ARE IN FRONT OF THE PROP.
Happy holidays...
12-23-2004 | 08:43 AM
#5
Senior Member
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RE: What!! no forum for engine ?'s
In case this gets moved, you can find it in the ENGINE FORUM under "GLOW ENGINES."
Dial in the high end as best you can. While the engine is running at an idle, pich off the fuel line with a pair of pliers or remove the fuel line from the nipple until the engine quits. If the rpms increase right before the engine quits. Your low end is to rich. If the rpms just go down and die. Too lean.
I try and get it in a very slight increase. Then dialin the high end again to check it. You may need to bounce between needles to bring it together.
After each time check the throttle transition from idle to full speed. Dont' "Jam" the throttle full speed but very fast progressive manner. The sound should be smooth with no "sputtering."
Dial in the high end as best you can. While the engine is running at an idle, pich off the fuel line with a pair of pliers or remove the fuel line from the nipple until the engine quits. If the rpms increase right before the engine quits. Your low end is to rich. If the rpms just go down and die. Too lean.
I try and get it in a very slight increase. Then dialin the high end again to check it. You may need to bounce between needles to bring it together.
After each time check the throttle transition from idle to full speed. Dont' "Jam" the throttle full speed but very fast progressive manner. The sound should be smooth with no "sputtering."
ORIGINAL: Gmonkey
I guess this is a good spot for engine questions. Could someone explain how to tell when to richen and when to lean the low speed needle valve? thanks.
I guess this is a good spot for engine questions. Could someone explain how to tell when to richen and when to lean the low speed needle valve? thanks.
