OS HZR Motors – How to prevent sticky regulator?

[cbrkhan]

Hi Guys,

I am new to Niro helis and I ran into possible sticky regulator yesterday. I landed my trex 700 after two minutes of flight and the motor was leaking fuel everywhere. My heli and motor are brand new with three flights them. I guess mine became sticky because there were 3 weeks between flights and I leave my heli with a tank full of fuel. Other threads suggest opening the regulator and cleaning with denatured alcohol.

I have OS91 HZR and OS105 HZR for the heli with 91 currently in it.

What can I do to prevent a sticky regulator while my helis sits for weeks waiting on next time I can fly?

Thanks

[Don S]

The manuals for the -R's says to run the engine dry at the end of the day.

[ticedoff8]

The main reason to leave your heli with a full tank is because you use muffler pressure to pressurize the tank while flying.
And, the residual exhaust gas eats the foam that is used on the fuel magnet clunks a lot of guys use.
So, you fill the tank at the end of the day to purge the tank of residual exhaust gases.
The HR-Z use crankcase pressure - which is clean and does not eat the foam on the clunk.

So, no matter, you don't need to fill your tank at the end of the day.

Also, as stated, fly the tank dry if it is the last flight of the day.
If I know it is my last flight, I will hover around until the engine starts to lean out and then land and let the motor die on the ground.
Otherwise, I will pump the remaining fuel out of the tank and then start the motor. Run it at a fast idle and let the blades spin up a little until it dies.

Also, use a good quality fuel.
Anything from Byron's Originals is great.
At least, look for fuel that uses at least 21% (by volume) of 100% pure synthetic oil.

If the fuel contains poor / low quality oil or a "blend" of synthetic / caster oil, the residual oil will gum up the diaphragm and fuel lines as the alcohol evaporates over time.

If you are using a decent fuel, you should not have to worry about the bearings rusting - especially if you fly the tank dry.
Rust comes from left over alcohol in the crankcase. The alcohol is absorbs water and when the alcohol is gone, the water remains.
Flying the tank dry means less alcohol left in the crankcase and what little remains flashes off due to the heated crankcase
And, the good, 100% pure synthetic oil protects the bearings from what little water might accumulate.

In other words:
Do what Don_S said.

[Drivelayer]

is there any risk of hurting the engine letting it lean out to empty the tank?

[banditpowdercoat]

No harm in running it out, as long as your not running it hard when it runs out. As for fuel in the tank. I leave it how ever it is at the end of my flying day. Usually I fill my tank, just so its ready. BUT, I always pinch off the line to the regulator, and run the engine dry. I put glow ignitir on, and crank her over and over and manipulate the throttle by hand. Heli electrics turned off. I have a throttle spring on so if I let go, she dies anyways. But ya need to manipulate the throttle while cranking to get her to burn all the nitro out. I store my heli 2wks to a month between flights while im at work like this. No sticking yet

[cbrkhan]

Originally Posted by banditpowdercoat

. I have a throttle spring on so if I let go, she dies anyways.

How does this work? Sounds Interesting


ticedoff8 - I am using VP PowerMaster

[banditpowdercoat]

Small spring connected to throttle arm. In case of servo or power failure. It closes throttle. I never run a nitro without one.

[cbrkhan]

Originally Posted by banditpowdercoat

Small spring connected to throttle arm. In case of servo or power failure. It closes throttle. I never run a nitro without one.

I would like to do this on my birds ... Just would feel safe .... Do you have a picture of how you attached it?

How did you decide the spring length and tension and then where did you get it from .... I would think too much tension would mess with the servo operation .... too little it will not close in case of power failure

I dont have springs laying around so I will have to get just the right one... I have a n5ctt and Trex700 nitro

[Drivelayer]

I have tried that but the spring keeps breaking, how are you fastening the spring? Also to get a spring strong enough to pull a dead servo closed I worry about too much stress on the servo during normal operations

[banditpowdercoat]

I use a high speed servo that doesn't have much unpowered pull force through the gears. And I just find long springs that just pull the servo closed or almost closed. The one I run now doesn't pull the servo all the way closed when engine off. But once running, the vibrations help it and it does close right off. It's a trial and error thing. I bolted the other end right through the chassis plate at a position that applied the right force.

[banditpowdercoat]

I'm at camp now. Had wife try take a couple pics.

[cbrkhan]

Originally Posted by banditpowdercoat

I'm at camp now. Had wife try take a couple pics.

Thanks you!

[Drivelayer]

Those are great, thanks

[ticedoff8]

Return spring:
Trex 700N with YS 120SR-X and Align DS650 throttle servo.

The last nitro I flew without a return spring flew away after the radio receiver battery ejected.
I haven't flow a nitro without one since (7 or 8 years ago)

[cbrkhan]

Heli flying away with no one in control ... Scary thought

[cbrkhan]

Any mechanical engineers here who can possibly provide spring specs for the job ...

Where would one buy springs ? Maybe I can just order some and play around with fit and feel

Really like the idea though

[Drivelayer]

I purchased a box of assorted sizes from Harbor Frieght for $5 .. hey maybe that's why the few I have tried keep breaking.


I had a Trex 700 that the power switch broke in flight, lost all control, luckily I just popped it up into a tic toc, it was near vertical and zero collective so it sat in the air for a second then dropped right down on its tail .. very lucky.


it did the chicken dance for about 3 minutes before dying

[banditpowdercoat]

I used a cut down 1/8 scale buggy exhaust spring.

[cbrkhan]

I just picked up this 200 spring assortment. One of them may just work out !


http://www.amazon.com/Neiko-Steel-Sp...ing+assortment

[banditpowdercoat]

Remember. Put the spring on the throttle arm not the servo linkage. That way if linkage pops in a crash, the spring is still directly connected to carb. Also if the spring is stiff, you can attach it lower down on carb arm to lessen the pull against the servo.