Cant shut engine off in flight?
06-28-2009 | 08:57 AM
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From: bellingham,
MA
Cant shut engine off in flight?
During a contest yesterday we were to fly to altitude, kill the engine and land closest to a target. I had a diffucult time getting the engine to stop..
After always having problems with my TTPro .36 idleing, this new engine is a TTPro .61 and its running great. About two gallons through it and it Idles very low.
I'm still trying to run it rich, tons of fuel spitting out the exhast. The only problem was tring to shut it down in the air. even after adjusting my throttle end points on the radio it wouldnt shut down.
I had to climb hard and slam the throttle down. took me a couple of passes to do it...
I have no problem shutting down on the ground.
Steve
After always having problems with my TTPro .36 idleing, this new engine is a TTPro .61 and its running great. About two gallons through it and it Idles very low.
I'm still trying to run it rich, tons of fuel spitting out the exhast. The only problem was tring to shut it down in the air. even after adjusting my throttle end points on the radio it wouldnt shut down.
I had to climb hard and slam the throttle down. took me a couple of passes to do it...
I have no problem shutting down on the ground.
Steve
06-28-2009 | 09:00 AM
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From: Oklahoma City,
OK
RE: Cant shut engine off in flight?
You may have to adjust the idle stop to allow the carb to close more. It's harder in the air because your forward movement through the air is turning the propeller. My electrics never fully stop unless I use the braking system in the esc which I don't like.
06-28-2009 | 09:12 AM
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RE: Cant shut engine off in flight?
Your ground idle sounds like it's to high. If you cut the throttle and pull the trim down all the way, it should shut down the engine. If not, then you will need to play with the adjustment, keeping in mind that it's a fine line between fully closed and binding the servo.
It will first be a mechanical adjustment, both full closed and full open, then an adjustment using end stop adjustments (electronic in the transmitter if you have a computer radio) for the fine tuning... again, watching closely for the servo trying to go beyond fully open and fully closed.
You should set it up so that with the throttle trim at the mid point, your engine should run at a decent idle of around 2000 - 2500 rpm. Then, if you have a throttle stop button or switch, or if you programmed one in with a mix (again, computer radio), you should be able to hit that switch or push that button, to bring the engine down low enough to "kill" it.
All this takes some time to set up properly without binds, so either do it yourself, or, if you have never done this sort of adjustment befoe, work with someone at your club that has experience and get it set right.
CGr.
It will first be a mechanical adjustment, both full closed and full open, then an adjustment using end stop adjustments (electronic in the transmitter if you have a computer radio) for the fine tuning... again, watching closely for the servo trying to go beyond fully open and fully closed.
You should set it up so that with the throttle trim at the mid point, your engine should run at a decent idle of around 2000 - 2500 rpm. Then, if you have a throttle stop button or switch, or if you programmed one in with a mix (again, computer radio), you should be able to hit that switch or push that button, to bring the engine down low enough to "kill" it.
All this takes some time to set up properly without binds, so either do it yourself, or, if you have never done this sort of adjustment befoe, work with someone at your club that has experience and get it set right.
CGr.
06-28-2009 | 09:37 AM
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From: bellingham,
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RE: Cant shut engine off in flight?
ORIGINAL: CGRetired
Your ground idle sounds like it's to high. If you cut the throttle and pull the trim down all the way, it should shut down the engine. If not, then you will need to play with the adjustment, keeping in mind that it's a fine line between fully closed and binding the servo.
It will first be a mechanical adjustment, both full closed and full open, then an adjustment using end stop adjustments (electronic in the transmitter if you have a computer radio) for the fine tuning... again, watching closely for the servo trying to go beyond fully open and fully closed.
You should set it up so that with the throttle trim at the mid point, your engine should run at a decent idle of around 2000 - 2500 rpm. Then, if you have a throttle stop button or switch, or if you programmed one in with a mix (again, computer radio), you should be able to hit that switch or push that button, to bring the engine down low enough to ''kill'' it.
All this takes some time to set up properly without binds, so either do it yourself, or, if you have never done this sort of adjustment befoe, work with someone at your club that has experience and get it set right.
CGr.
Your ground idle sounds like it's to high. If you cut the throttle and pull the trim down all the way, it should shut down the engine. If not, then you will need to play with the adjustment, keeping in mind that it's a fine line between fully closed and binding the servo.
It will first be a mechanical adjustment, both full closed and full open, then an adjustment using end stop adjustments (electronic in the transmitter if you have a computer radio) for the fine tuning... again, watching closely for the servo trying to go beyond fully open and fully closed.
You should set it up so that with the throttle trim at the mid point, your engine should run at a decent idle of around 2000 - 2500 rpm. Then, if you have a throttle stop button or switch, or if you programmed one in with a mix (again, computer radio), you should be able to hit that switch or push that button, to bring the engine down low enough to ''kill'' it.
All this takes some time to set up properly without binds, so either do it yourself, or, if you have never done this sort of adjustment befoe, work with someone at your club that has experience and get it set right.
CGr.
I have the throttle body fully closed with throttle and trim all the way down. I'll double check that I'm not binding the servo..but the throttle is closing...
Seems like I cant close it anymore. but the engine keeps running ( in the air )
06-28-2009 | 11:11 AM
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RE: Cant shut engine off in flight?
I would go with an air leak too. I was having this problem a few weeks ago with an engine and a friend told me to chase it down like a leak in a water heater gas line. I took soapy water, hooked up a long piece of fuel line to the carb, closed the carb all the way then brushed the soapy water around the carb and blew into the fuel line while looking for the bubbles. Shazam, there they were just bubbling away!! Once I found the leak the fix was easy. It can be something as simple as a bad O-Ring under the carb or on a needle valve. Give it a try ans see if you can find a problem.
06-28-2009 | 11:26 AM
#8
My Feedback: (-1)
RE: Cant shut engine off in flight?
All the gas lines I have checked over the years with soapy water and never thought about doing it on an airplane engine just baffled me. Why didn't I think of it long long ago?? When my buddy mentioned it to me the thought landed on my brain like a brick!! DAHHHHHH
