RunRyder - Help me plz wit my YS 91SR

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Synergy R/C Synergy N9 > Help me plz wit my YS 91SR

ch-47c
Senior Heliman
Location: san jose, ca

This is my first YS and I finally ran it up the other day. I'm getting old and lazy so I need help. I felt like a 14yr old boy on his first date when my Synergy was running up and started smoking like a greasy Weber. All the fuel lines and all 3 needles were set to factory instructions. It smoked real nice at idle and running up until around 30% stick, when the smoke dissipated and looked lean and it sounded like 2 cycle going in and out of 4 cycle. I thought it might be a transition problem between the low and mid needle settings thing. I enriched the hover(mid) needle several times until it was around 2.5 turns with no improvement. I cut back the throttle each time to avoid a lean run. Any ideas? The check-valve out of the backplate to the tank has a little triangle embossed/stamped on one end. I set it in the fuel line so that it is pointed towards the tank. If this is wrong, could this be a factor where the pressure to the fuel tank isn't up to what the regulator needs and goes lean to the carb, because the tank pressure is low with a backward ck-valve?

Thanks guys. I know it is best to ask Synergy guys because this board seems to be quite civilized in the postings.

07-23-2008 12:18 PM

mdu6
Veteran
Location: Montreal

The one-way valve is set in the right direction (V toward the tank).

At the end of the flight did you release the pressure in the tank and noticed a good volume of air got out (standard pssssssssssst sound !).

If not, the one-way could be defective, tubing or tank fittings could be leaking.

Other ideas, ... make sure the tubing from the crankcase to the one-way valve is 10cm long.

One last point, are you sure you open up the mid needle (hover) and not the high ?

07-23-2008 01:25 PM

ch-47c
Senior Heliman
Location: san jose, ca

mdu6,
Yes it went pssssssssssssssssssssssssst. All new Aerotrend line my favorite. The clunk grommet didn't leak any fuel like many others complain of and replace with an Align grommet.
The line from the crankcase backplate is 10cm long as per the instructions.
Yes I adjusted the mid needle, the big one as per the instuctions.

My buddy said when it shuts down, the cluck lets out a stream of air bubbles from the clunk into the tank.
More plz more..........

07-23-2008 01:54 PM

mdu6
Veteran
Location: Montreal

You could be running too high on the carb, put your stick back at your hover position and see where it is on the carb. YS indicates a hover at around 40% on the carb.

That's a "long" shot because even if you are at around 60%, the hover needle should have some effect.

That's the only other thing I can think about (beside a faulty engine or dirt in the carb/regulator).

07-23-2008 02:20 PM

RyanW
Veteran
Location: Stillwater, Oklahoma

If it doesn't run at break-in settings, most likely it is an external problem.

Are you using a gov, rev limiter or carb mixture adjustment? If so, I would leave them inhibited until your engine is well seated.

07-23-2008 03:31 PM

HOMEPAGE

ch-47c
Senior Heliman
Location: san jose, ca

I read somewhere on RR to ignore the 40% mark and go higher.
I'm running a GV1. I will inhibit it and use my Normal throttle curve which right now is set linear. It is my first time to use a govenor. I'm old school last flying regularly back in 1999, but I like technolgy. Right now I'm out of town and won't get back for a week.
Any more suggestions no matter how basic or obvious are accepted and appreciated. This YS system is new to me. I've used all sorts of other pumped and non-pumped systems. Will try all suggestions until it works, which I know it will. I just need to find the bug.

07-23-2008 03:42 PM

baddraptor
Elite Veteran
Location: valencia, ca- usa

Turn the gov OFF until it is broken in. It may be contributing to your problem. Start over at factory settings and tune from there.

**Unattended children will be givin a shot of espresso and a puppy**

07-23-2008 04:00 PM

Chuckie
Key Veteran
Location: Crofton Maryland, MHA member

Quote
I will inhibit it and use my Normal throttle curve which right now is set linear.

Even with a gov the normal curve should not be linear. If the gov or sensor fails the curve will be too high. Use a 'J' throttle curve where half stick the value is 40 and 3/4 stick is 55 to 60%. For example with a 5 point curve use 0, 15, 40, 55, 100.

With a 7 point use something like:
0 10 30 40 45 55 100

With gov off at 55% the N9 should hover at a low head speed, especially with the rich factory settings. Adjust that one point to change the hovering head speed. Like old school set the curve so the rotor reaches your desired target speed at 1/3 stick then as you go from half (zero pitch) to hover the head speed doesn't change.

Charles

Please stand by for faster service!

07-23-2008 05:34 PM

ch-47c
Senior Heliman
Location: san jose, ca

Sorry guys, when I said linear I meant 0,25,50,75,100 not 100,100,100,100,100. I usually set my Normal as above, Idleup1 15,25,50,75,100 and Idleup2 100,75,50,75,100. When I fly it I adjust the curves to prevent overspeed and bogging. My helis have always been fine once adjusted.

What do you set your 3 curves for setup and ready for the first flight with a gov installed?

07-24-2008 01:45 AM

airboss
Elite Veteran
Location: OC ,california

your midstick is too low on your curves. my set up is ,
norm;0 25 65 75 75
1 ;100 75 100
2 ;100 85 100
YSsr 91/sb19
multi gov/1950
high needle;7/8
low needle ;1 1/2
CP 30%

OCRM....flyBlackstarr.org.

07-24-2008 02:29 AM

Chuckie
Key Veteran
Location: Crofton Maryland, MHA member

I understood linear to mean 0, 25, 50, 75, 100 and the point is the motor will overspeed on the ground and while flying with this kind of throttle "curve" when the gov is off (unless your carb is set very rich). At mid stick the blades are at zero pitch, if you fly a linear pitch curve with zero in the middle, then 50% throttle is too much. I should clarify, if you want to hover at 1900 to 2000 then its ok to run that linear curve.

YS put the 40% mark on the carb to help the user set the throttle curve correct on the bench. However, today we fly at higher head speeds so the mark is not really that useful.

The 3/4 throttle stick point is closer to the place where you hover so setting that point directly affects the hover rpm. I have noticed that 55 to 65 is a good starting number for rpms in the 1750 to 1850 range. With today's headspeeds the tx point is closer to 5/8 so one would have to adjust the mid point as well. For idle up 1 and 2 just pick a slightly higher 3/4 throttle value so you hear the rpm go up when you fly the different idle ups; 60, 65, and 70 for example.

airboss, For the first flights on a new motor and new machine I wouldn't recommend your values. My throttle values are just starting points but are meant to set medium speeds. RPMs will be different if you use a different pitch curve or setup the throttle linkage differently. Also, the carb setting affects the hovering rpm. As a back up curve to the gov I wouldn't recommend 85% at mid stick. If the gov fails I would rather hear the motor rpm drop versus overspeed.

Regards

Charles

Please stand by for faster service!

07-24-2008 12:32 PM

ch-47c
Senior Heliman
Location: san jose, ca

OK guys I try it when I get home and let you know what happens. Thanks again.

07-24-2008 09:33 PM

Rockohaulic
Elite Veteran
Location: Valencia, CA, USA, 3rd Rock from the Sun

0-25-50-75-100 is way too high.

Chuckie's curves are much better:

For a 7 point throttle curve:
0 10 30 40 45 55 100

I got a helicopter for my girlfriend,
It was a good trade!

07-24-2008 10:33 PM

Chuckie
Key Veteran
Location: Crofton Maryland, MHA member

I suspect the gv1 wasn't working hence the high rpm.

Please stand by for faster service!

07-25-2008 12:12 AM

ch-47c
Senior Heliman
Location: san jose, ca

Somehow this thread got a different life than intended. I don't want to write a long explanation. I always start any never been flown heli with a 5 or 7 point throttle or pitch curve linear. This could be called a nominal curve. It is a base setting and I always know where the heli is to start and go from there. I'm an old school helicopter mechanic and start things nominal unless the manufacturer allows otherwise. This gives me a consistent baseline to work with as I am only human. Remember i said I am old and lazy now days. I have used this since 1985 and it has worked fine for me always. I start adjusting the curves immediately as needed on the first flight and usually have it set by half a tank or less. If it is a first flight after a crash that flew fine before, I usually keep the curves and adjust as necessary, if needed at all.

My question at the beginning was about fuel flow and mixture on a YS.91SR, not curves. I found out what the problem is with troubleshooting techniques not in the instructions. The checkvalve has an arrow or more appropriately described as a diamond on its side. It is supposed to be pointed in the direction of intended flow. It points in both directions. Because it is a diamond and not an arrow, it points both in and out. It must be on the outlet side of the valve. I took it apart to see which end is really what. I felt it was the problem first because of rich needle settings and lean run an appx above 1/3 stick. I pulled the ck-valve out, took it apart, reassembled it, and attached a fuel line to it and submerged it under water. It bubbled one way like it was designed and I hooked it up. It runs fine now.
Thanks again Synergy guys for all the help.

07-28-2008 02:47 AM

mdu6
Veteran
Location: Montreal