Spectra G. Toxic 231, GY401 help.

[Zman39]

Hi All,

Here is my situation, hopefully we can come up with some idea to try. I have a new spectra G with the toxic 231 with the latest version of century pipe on it. I am using a 401/9254 servo/gyro and also using a CSM gov with stator gator. I ran the first gallon per instructions using lawnboy ashless. After first gallon, I switch to amsoil sbalre professional mixed at 50:1. here is my problem(s). I am running 1600 in idle 1 and 1700 in idle2.

At hover, the engine sounds like it is "missing" and when it does the tail kicks with it. I also have set the 401 up per instructions, no subtrim, no revo, and in HH the nose drifts to left in hover. On full power climb outs the engine sounds better and the tail holds and no visable kicking. As I start to bring it back out of forward flight the engine start to "miss" and the tail kicking starts again. My needle settings are 1.5 out on low and 1 3/8 out on high. Plug show a good milk chocolate all the way around.

Any help much appreciated.


Mike

[bigrcr]

Try leaning the low end a bit at a time and see if that makes a difference.

Later,

[Zman39]

Thanks John,

I went down as far as 1 3/8 but didnt make much of difference. I should mention however that I am using the MA air filter and the bottom half is getting a bit oil soaked, not sure if that is normal or not but figured I would mention it.

Mike

[ddavison]

Sounds like it is still too rich, As John said lean the bottom down a little at a time and leave it there for awhile. The air filter should not be getting wet. Mine is still dry and clean after almost two years of use.

[Zman39]

Okay, will do. I was hesitant to go any further due to the break in instructions saying never go leaner than 1 3/8 but I will give it a try. Thanks all.


Z

[Zman39]

Also was curious, would a faulty carb insulator that some have replaced with the Z-rc cause any of this?

Mike

[rbort]

Just lean the low end some more. I think you can go down to 1 1/4 with no issues.

Carb insulator should not be a problem unless its cracked. In most cases people replace it just because they want the bling bling upgrade.

-=>Raja.

[ClayK]

I found the standard block warped due to heat. I replaced it with the z-rc insulator block. I was chasing a tuning issue for a long time and it was due to an air leak.

Your problem however sounds like it's too rich. I had 1 3/8 as a starting point on both needles.

[Zman39]

Thanks guys, I really appreciate all the help!! Hopefullly willl get to try leaning it down tomorrow or day after. Thanks again

Mike

[rbort]

Let us know how it all works out. I'm flying mine at 1650rpms in idle up 1 and the machine really likes this rpm.

-=>Raja.

[Zman39]

Thanks will do, 30 mph gust and rain today so maybe do a good pm on heli and hope for better tomorrow. Thanks again guys and Merry Xmas.

Mike

[Zman39]

Well I leaned the low end down and still having issues. This time I tried from 1.25 to 1.75 to cover the range, still had issues of bad tail kicking. The best I got it to behave was in normal with no governor on. It sounds much smoother but only for about 5-10 seconds and then the head speed starts taking off. If I flip the gov on, it controls the head speed but the engine sounds bad (not smooth)which in turn makes the tail start kicking all over. :arggg:

Mike

[bigrcr]

First try running the motor without the governor until the motor is broken-in or nearly so. With the governor on you cannot really tell how the motor is responding and if there is any lean condition, the governor will "force" the motor to cooperate.

Does the motor run smooth at all? Are you chasing needles to get the tail to cooperate? The reason I asked is that I personally never got a GY-401 to work in a Spectra-G as the tail was always unsteady. Using a JR 500T or a GY601 was the ticket.

If the head speed is taking off, either the governor is "forcing" the motor into a RPM and making it lean or the needle(s) are too lean at that point. Either way, the increase of RPM at a single setting is an indication of leaning. An air leak or muffler leak will cause the same.


Later,

BIGRCR

[Zman39]

John, thanks for reply. The only time the motor sounds smooth is in normal mode that I have set with no gov and a 1600 head speed. It will come up in hover and sound descent but that is when the head speed starts taking off. I dont know if it is sucking air or clearing itself and getting itself on high needle. As with a lot of gasser, my curve is something like 0,15,20,26,100.

Bummer on the 401, hate to hear that but if purchasing a new gyro will allow me to start having some fun I am all for it :D

Mike

[rbort]

I'm setting up a Spectra-g for someone else -- taking it to fly at the field today. He has a 401 gyro and I replaced the solid Futaba square tape with zeal tape. One thing to note on the 401 if the gain is too high it will shake the tail. Reduce the gain some. Mine is set to 50% on his Futaba TX in the gyro screen.

Throttle curve sounds about right. I'm running his at 1650 rpms and it seems to be nicely settled in at that rpm. I was hovering it in the backward and adjusting engine needles, gyro mechanical trim and some other things.

The 401 gyro will work though its not the best. I tried the 401 on my Spectra at first and never really got the tail to settle down 100%. I switched over to a 611 gyro soon afterwards and that works much better. I put the 401 in my T-rex where is serves its purpose better now. But don't rush out to buy a gyro just for that -- I am pretty successful with the 401 in Mel's heli so you should be able to get by with that though I prefer the nicer gyro for this machine.

If it speeds up check the throttle curve. The gv-1 will hold down the rpms but you can turn off the gv-1 and see if it holds steady or speeds up. If it speeds up then either richen the low end or lower the throttle curve some. If its burping then you need to lower the curve, if its not then richen the low end.

Basically what you want to establish is a throttle curve where on the gv-1 you are hovering and then you turn off the gv-1 with the gear switch for example and there is no change in rpms. Do that for all modes (normal, idle up 1 and 2) and then you are set.

I pretty much fly on the gv-1 from day 1 as I know how to see what is happening with the engine and gv-1 (by using the on/off switch) and adjust the engine/curves accordingly.

-=>Raja.

[rbort]

Oh yeah, also make sure you do the "little stuff" before you concentrate on the tail. Meaning you balanced the blades with a good balancer (koll rotor pro for example), you tracked the blades 100%, not 90, but 100% as even slightly out of track blades will cause vibration and make it harder for the gyro to work properly. You eyeballed the flybar paddles in flight and they look tracked. If they look wider than expected or out of track then land and recenter them. You adjusted the mechanical setup for the gyro so at your target rpms there is no drift in normal mode, and you setup the end points on the gyro for max throw without binding.

Set your failsafe to idle and zero collective centered cyclic. Set your gv-1 limits again after you have established a good idle (changes with mixture changes) and turn on battery failsafe on the gv-1 and set it to 20% power on failsafe.

P.S. Don't forget to put a couple of plastic washers under the pivot screw of the choke if you are using the stock box as if not over time it will loosen an the choke will close in flight. :shock:

-=>Raja.

[Zman39]

Thanks,

Right now I am using the MA air filter. Even after mechanically getting gyro to hold in non HH mode, I still get a bit of left drift in HH mode but the drift seems consistent with the tuning of engine. Otherwise, everytime it "misses" (for lack of better term) the nose drifts a little to left.

The blades and paddles are dead nuts tracked. I refuse to give up but man I never had this much problem settling in a heli. But it is my first gasser and MA for that matter but I am sure the MA part isnt whats causing the problems. Got to be either gyro or engine.

Mike

[CitationX]

I will be very interested on the outcome of this thread. Not so much from a Spectra-G standpoint but rather with my Vibe and OS.91-SZ. The "misses" that Zman is describing and the associted tail kick is EXACTLY what I have been experiencing since day 1 (almost 11 months ago)!!! Anyway, I have been told to chase it down to balance and runout checks, etc. So I will be curious about the outcome of this thread and see what I can apply to my Vibe.

Thanks guys

[Zman39]

Well, I put on a z-rc insulator in case I was getting an air leak there and went out for a test flight. I brought it up in a hover around 1600 in normal mode (no gov)and it was pretty smooth including the gyro. This lasted for about 30 seconds and the head speed took off on me so I flipped it in idle one which is set at 1600 and the engine started making the noise again but this time I stood next to it and watched the throttle servo and it was going back and forth as well. Now which is causing which on the gov no idea but clearly if the throttle servo is going back and forth then that is going to make the engine sound bad. But still doesnt explain the head speed taking off all of sudden in non gov mode (normal). :arggg:

Mike

[carlos]

I believe if the engine is racing it is running lean.
Have a look around the cylender base gasket and also the crankcase halves, if you see any black or oily areas then there is a good chance there is a leak from there. Also check the crankshaft seal area.
Although the 401 will work in the Spectra (marginaly) There is a definate engine problem with your machine.

[rbort]

Replace the throttle servo. That is the root cause of your problems and it explains everything.

-=>Raja.

[Zman39]

Replace the throttle servo. That is the root cause of your problems and it explains everything.

-=>Raja.

Raja, servo works fine in normal (no governor mode), it only does it when the gov is activated. May be a bad CSM RL10 or stator gator?


Mike

[Peter]

Have you closed the plug gap down to around 20 - 22 thou ? Some of them , out of the box , are way to wide ....

And its pretty common to have to use some Rudder subtrim if you have a 401 and a JR transmitter , to get rid of any drift in HH ; even after the rod length is set in rate mode ...

[Zman39]

I will check the gap, thanks. I am using the 9C with the 401, I only get the drift if the engine/throttle start acting up. In non gov mode the nose holds well, just when I switch on the CSMRL10 does the nose drift and the engine starts acting up and the throttle servo starts moving back and forth. I am starting to think it may be the gov or stator gator?/

[rbort]

Vibration will cause a bad servo to "jump around". Could still be a bad servo.

As far as the gv-1 , maybe you didn't set the limits, changed settings in the hidden menu, didn't adjust the throttle curves properly, or mixture isn't right. There are many factors for that.

The stator gator you just start the engine and look at the gv-1 rpm screen. It either works or not. If it works then you got rpms. If not then something is wrong.

Gotta run...try some things and I'll respond to your findings later on.

-=>Raja.