N7 with 105 tunning issues and run times?

[Mike Spano]

it is my understanding that it could be one of two things.

1 - this needle seat was simply machined wrong (this is my opinion)

2 - this motor was intended to be run on 30% nitro, meaning it needed more flow from the needle. (this seems to be the stance they are taking now. i gathered that from the linked post above...)

[Chris Sexton]

Yeah well I ran 30% on my 105 it still tuned like crap with the bad seat.

[Mike Spano]

i believe it was machined wrong from the start. i was told that whoever passed out the needle seats at IRCHA stated that.

[beans07]

I took the N7 out today for a run. I have removed a shim and decided to start and some leaner settings. Started at 1.25 on main and 1 on the mid. Instantly felt better but still rich. I got the main into 1 turn and about 3 clicks out.

I had a lot of trouble with check valve getting fuel and causing it to lean out. I put a new one one and the thing is an animal now!! Very happy although on the 4th tank right near the end it just cut out in a big powerloop only a couple of meters off the ground, I flipped it over but it hit hard on the skids. Broke a couple of transmission gears, the tail fin and the landing gear. I am a bit surprised on the damage considering it wasn't any more than a hard landing on it's belly. Just unlucky I guess.

Really not sure why it cut out. Glow plug was clean and looked brand new, which was put in the last flight I flew the helicopter before today. I have a suspicion it's a clunk or clunk line thing.

I have a couple of issues that some of you Synergy Guru's may be able to help me with. I keep getting about an inch worth of fuel in the check valve line that then blocks the valve and then the heli runs lean. It happens on both my OS 55 HZ-R N5C and OS 105 HZ-R N7. It drives me mad.

I am running a MOAS and black hayes clunk line in both N5C and N7 (ran it in helis for many years without issue). I don't seem to have any clunk issues with the N5C which runs to within 1mm/2mm of the back of the tank.

On the N7 I have it to the front edge of the slanted part of the fuel tank. I tried to the back but it wouldn't get into the fuel in front of the slant. Now it's at the front I have a suspicion that today the MOAS was out of the fuel when the engine cut on me when the heli was in a sort of upright position. The fuel would of been from bellow the edge of the slant to the back of the tank.

A couple of question's for the Synergy Guru's.

1. Why do I keep getting a lot of fuel in my check valve line?

2. What clunk line, clunk and length are you guy's running? What can I do to stop it flaming out on me in the future?

[beans07]

[Kevin Dalrymple]

For the fuel clogging the one way valve, i would not use a T for my vent. On my N7 I just pull the tubing off the valve next time you fill up. You can try this to see if it would work before you change any hose routing.

The way you have it now fuel could spill into the one way valve.

As far as flame out, is you fuel foaming in you tank?  When hovering?

[beans07]

Thanks for the tip. I haven't always ran this way and when I think about it the way you describe is the way I had done previously and don't remember problems.

As for the fuel foaming. No it is running very smooth, there is no foaming of the to k and the no  irrational at all in the tail fin. One of the smoothest nitro helis I have ever had.

[Chris Sexton]

I run a T in my pressure line, but I haven't had any fuel int he pressure line issues.  I also make sure I don't fill the tank to the point fuel is touching the nipple.

[beans07]

It's not filling the tank that's the issue. I am pretty it happens after I start and carry to the flight line.

[beans07]

I noticed that today there was a little more high resonance vibration and a little bit of foaming in the tank. Don't recall seeing it before.

As I tuned it more it got better. When I installed the fan and clutch originally I think the hub was a little warped so both fan and hib need replacing which will help fix that little bit of vibration.

I am thinking of using some lynx fuel tubing and go to the back of the tank as it still cutting out towards the end of the tank when doing loops.

[beans07]

Ok so I changed out the clunk to an OS bubbless and some lynx clunk line that is very soft. The heli didn't lean out until there was only a couple of drops left. Very happy with it now and it is performing very well. I think with the MOAS being so light it was jumping out of fuel at times, causing issues with the tune, the tail, and governor. Now the engine sounds great and is very happy when loaded up, comes down cool and less vibration. With the VBC and the governor it is working very very well. Really loving flying this heli.

 

[Rodney Kirstine]

That's great news!

[Ross Lawton]

Thats fantastic news!! 

I use the OS Bubbleless clunk myself and have had nothing but good results with it. Keep us updated and happy flying!

Cheers,
Ross

[beans07]

Thing's were going well for about 6 flight's until a cyclic servo failed one me.

Thus far I have an RJX tail servo randomly die after about 20 flights and now a cyclic when I have hit about 40 flights. The only electric's on it are servo's and a vbar unit and vbar control receiver. I would think it to be strange that the vbar would be killing them, there is no binding at all and gain around 70.

Anyone have any issues with RJX servo's failing?

[Chris Sexton]

Thing's were going well for about 6 flight's until a cyclic servo failed one me.

Thus far I have an RJX tail servo randomly die after about 20 flights and now a cyclic when I have hit about 40 flights. The only electric's on it are servo's and a vbar unit and vbar control receiver. I would think it to be strange that the vbar would be killing them, there is no binding at all and gain around 70.

Anyone have any issues with RJX servo's failing?

My N7 started with RJX servos. I had a tail and cyclic both go dead in the first month or so.  That said, I have a set of RJX on an E5 with 150+ flights.  Not sure what to think there.