What's your idle at?

[RontaryUS]

I am idling at 11-13% throttle on my os37 engine. This is quite higher than what I am used to with 90 size engines. I cannot maintain a good idle under these values. Played with the mixture, checked fuel lines...

What is your idle at?

[u8at711]

check or clean your carb, maybe you have a blockage in the idle needle port.

I normally set my motor at factory settings, then set the idle needle rich, after idling the motor for a minute or 2 the motor loads up, this makes it choke out and stall. I back off the fuel until a good idle is achieved for a long period, maybe 4 - 5 min. some people use the pinch the fuel line trick to see how long it takes before the motor increases speed and stalls,
this does me no good, if I start my motor and have to carry the heli to the fight line, it's about 200 foot walk.
set the high by flying it and loading the motor, tic tocs, ect.

also check for leaks, in fuel lines, carb gasket, carb screw, loose plug, leaky pipe, tank pressure fittings and tubing, head bolts, back plate bolts. check the top hole of header tank for blockage, sometimes the fuel pinch off fitting kinks the fuel line, that starves the motor. could even be a bad glow plug,,,, I hate that,
things I found that kill glow plugs, Lean runs, rich runs, rust in motor, motor bearing starting to fail, bad carb seal or leaky motor, this includes the exhaust pipe seal.

try fresh fuel... just some things to try,,, learning how to tune and care for the motor is discouraging, just like learning how to hover the first time, but one you get good at it, it's hard to walk away from it.

[RontaryUS]

Thanks u8

Still curious to know what is nx4/os37 users idle at. Seems like this little engine needs rpms at idle to maintain it stable.

[jaofos]

Im usually at 13-15% throttle on my DX8?

[SMJT]

I got mined idling at 17% it maybe a bit high but it works.

[RontaryUS]

Great, so it looks like this verify my assumption this little engine needs quite some rpms to idle.

Any other to chime in on their % throttle at idle?

[u8at711]

If it's not raining tomorrow afternoon, I will hook up the Bluetooth to the vbar, and get a number for ya.

[RontaryUS]

Thanks u8, looking forward to your report.

Btw: you burnt 27 gallons of nitro ytd!!! You are the example of the fact that flying nitro saves money vs. buying batts and flying electric completely depends on how much you fly!!!

[jclutch]

I have a CGY750 running my NX4 and it shows the engine rpm on the display in real time. Mine idles for as long as I want at 700 rpm with the clutch disengaged. I've had the idle set as low as 600 rpm but it's lumpy and inconsistent.

[u8at711]

Vbar said, 540-600 bouncing, anything lower it got too choppy and could not stay running if the HELI was being carried.

I still fly electric, usually just to keep my packs healthy, once a month lol.
The price for large lipo's of great quality is not in the budget for me.

Check flight pack voltage, fill the tank and fly is so much easier,
No more generator needed for all day flying,

About 7 gallons to 100 flights on this nx4, calculated from cc per gal.
With 15% nitro that's around 160$. = $1.60 per flight. One day of flying costs the same as lunch, lol

[RontaryUS]

Jclutch, u8, what's your throttle % value on idle (assuming your low endpoint is closed carb...). Cannot log on my FBL unit so cannot compare RPMs...

Thanks

[jclutch]

I set up my throttle as per Ron Lund so my low throttle is pretty much idle and my throttle cut actually closes the carb to shut the engine off. So my low throttle is 4% on a Futaba 8fgh and that's my idle throttle position. Ron Lund (heli proz south) suggests that 50% stick position be set in the middle of the carb fully open and idle. That puts me at the carb being 60% open at mid stick rather than 50% at mid stick. So my bottom stick idle throttle % will read different from yours. As long as your engine will idle consistently without the clutch being engaged don't worry about it. The Ron Lund set up puts mid stick throttle position higher where the servo travel and throttle response are most responsive making he the heli feel like it has more power. It's on his website if you wanna try it out, I instantly noticed a difference.

[jclutch]

When I had a normal throttle set up with the carb closed at low stick and fully open at high stick my idle was between 18-24% depending on how rich my idle mixture was.

[RontaryUS]

Jclutch, thanks.

On my nx4 I have an ikon. On another nitro bird, I have a skookum and in the setup, you set your 0 throttle at the idle point which end up giving the same result as you describe from Ron's way of setting up the throttle.

I can probably do this with the ikon on my nx4 by playing with the min throttle in the setup. Will give it a try. Although I am not sure it will give more power as i am running a gov (the feeling of more power makes sense if you are not using a gov as it moves your throttle curve up per say).

[jclutch]

Even with the governor on, having the throttle linkage set properly gives the heli better response which makes it feel more powerful. I couldn't believe that it would make a difference until I tried it. Having the linkage at 90degrees from the arms (carb and servo) at mid stick gets the most responsive part of the servo's throw where the governor is going to use it. Having center be between idle and full power again puts the governor in the sweet spot of the engine's throttle response allowing the governor to work quicker and more efficiently. The heli feels like it has a lot more pop and the engine recovers instantly after loading. Setting up my throttle this way has allowed me to run lower head-speeds (normal-2340, idle-up1-2440, and idle-up2-2540) and have longer flight times because of the lower head-speeds. I'm also getting a lot better collective management and control because the head-speed isn't causing me to over pitch maneuvers. The lower head-speeds have also allowed me to increase my cyclic and rudder gyro gains making the heli more stable. Just that one change has made a dramatic difference in how the whole heli works.

[RontaryUS]

I read details on Ron's website. i got the point, makes sense, good tip.

[u8at711]

Don't know if my throttle setting would help you out at all,
Running the vbar gov, I have my linkages and idle set per the vbar guide.
My normal flight mode is only for starting the motor, and keeping in within the vbar parameters it will allow for auto bail out or soft spool up.

Ok this is on futaba radio and vbar
My throttle closed is at -114 and idle is at -98
Don't use my settings for setting up vbar- they could be wrong, check their website.

I know you don't have vbar, so this is just jibberish, lol

[RontaryUS]

I think I'm fine, looks like my idle at 11-13% is well within the norm. Was just worrying it would be high as 90 engines idle much lower. Thanks for sharing guys.

Jclutch, i just checked and my 700n is actually setup 'Ron's' way. I must have seen this somewhere when I built it and forgot since...

However, it is not on my NX4, hard to setup this way with the fan shroud or the pipe in the way of the carb arm...Any picture on how you get it set? If I put an extension on the carb to get it out of the way of the fan shroud, it is kinda offset from the servo arm...

[jclutch]

Just put the linkage on the bottom of the servo and throttle arms. When doing it that way you don't even need the spacer. Sorry, I have no idea how to post pics.

[jclutch]

By on the bottom, I mean the linkage being down by the muffler rather than up by the fan shroud. I used a futaba servo arm and the os throttle arm with the balls on the outermost holes. No spacers needed and just enough clearance from the exhaust header.