I have a new Bme 102 in a H9 extra that I cant get to run right.
The first flight was with a pro zinger 26x10 turning 5700 it ran fine on the ground but seemed to run lean in flight,,, it ran very erratic, On my second flight it ran the same way.. When I did a snap roll the plane suddenly lost all power,, and I couldnt advance the throttle to more than idle.. it went in...I snapped the carbon fiber gear and broke a prop,,

After I replaced the gear with the stock aluminum gear, I flew the plane again today with a Menz 26x10 and adjusted the motor as per BME's instructions, they claim I should get around 6400 turning the menz prop. I could only get 5800.. I flew the plane and It did not run erratic like the first two flights but on my second flight of the day I attempted another snap roll and the same S**t happend the motor lost all power..I thought I was deadstick but as I got the plane closer I heard the motor still running. after about ten seconds I was able to throttle up again to come around for an approach as I was coming around the motor lost power again,, I barely made the runway,, I came down level but hard and snapped the aluminum gear and broke another prop...
Two sets of gear and two $40 props later........
Does anyone have any good advice, Thanks

Hi airspeed917 it sounds like the ignition battery is going dead. I had a BME102 and I ran a 4.8 1500 mah pack and I could only get two flights and the engine would either quit or would go to idle. I couldn't figure it out at first because if the engine quit on me and I landed I would restart the engine and everything seemed fine. The voltage was also fine on the pack but it just kept on doing it so I put in a 6 volt 1650 Nmhd pack on the ignition and it cured the problem . I also was only getting 5800 rpm on a RCS 26X10 prop but as soon as I changed the battery to a 6 volt my rpm's jumped to 6500rpm. I hope this helps .

I definitely would check the battery to be sure it CYCLES ok. My BME doesn't need 6 volts, but it DOES need a good battery that delivers the juice.

The needle setting per BME instructions is a starting point, and further adjustment will probably be required for your area (settings would be different at sea level Miami, than at mile high Denver, right?). When you "landed" was the engine hot (as in lean running?) Can you restrain the plane and duplicate the symptons on the ground (except for the snap roll, of course!). Fuel lines pinhole free? Clunk sitting in the tank so as to allow free fuel passage in any position (and not get too close in "a certain corner"). Vent line open and free? How is the mid throttle running? Slight blubber, or is it clean? If you don't hear a slight blubber somewhere in the middle, the low speed needle might be a bit too lean, especially on a new engine.

The Pro Zinger is a good prop for the BME, and you'll see almost 6,000 rpm as you engine comes in. The thrust at 6,000 is the same 43 pounds as the MenzS26x10 at 6,400 (per my Walmart digital fish sca.......er.......THRUST METER!). Downline braking with the Zinger is a lot better though, and it hovers several clicks lower, and has a more "bounce" when the throttle is moved a couple of clicks while hovering.

I'll check the battery. I'm using the high capacity A cell's 1400 nicads, I think its a carb problem though,, its weird I rolled the plane with no problems to the engine,,but as soon as I snap rolled her,,it lost all power????

Is this a PCM reciever in your radio? Reason I ask is that in mine(Futaba) there is a feature that will lower throttle to idle for a brief amount of time when the flight-pack is low. This is designed as warning indicator of low-battery of radio.

When you say you snap-rolled it, and it went to idle, possibility I'm thinking is that using all servos for snap, it depleted the power enough to enable the "safety/warning" feature of your radio.

Just a thought here, it does sound like a power prob of sorts though, whether it be ignition or flight-pack. Good luck.

Wow Didnt think of that,,, I'm using the JR matchbox's, I have one
on the rudder and one on the ailerons,, this box allows you to have seperate batteries for the servo's its controlling,, I have a battery pack just for the ailerons powering 4 servos.. and I have another pack powering the rec/rudder/elevator.. so in a snap roll the battery pack is providing power to 4 digital servo's and the receiver at once... Hmm Correct me if I'm wrong but doesnt the PCM rec only act like that when the FAILSAFE feature is in the active mode? I believe you can inhibit that feature from the transmitter.... Am i right? Ron

Fail-safe is a feature that goes to pre-sets if signal is lost. In Futaba's there's another step that is a low battery indication, and that is a throttle-down mode.

This is reset in flight by going to idle on transmitter and throttling back to get your bird on the ground safely. It's really a different feature then fail-safe, as fail-safe is for loss of signal, throttle-down is a low power warning.

You still haven't said what brand trans/rec your using, I'm curious. I did read your using JR matchboxes, I would guess your with JR all the way here, but what is it anyways?

I'm not well versed on JR equipment so I really can't offer anything there. However, I've been using Futaba for 20+yrs, and have seen them evolve, and evolved with them. If someone gave me a JR transmitter to set-up, I'd have to learn that system, I can and do offer help readily with Futaba though where I'm able. Always learning though.

Yes Dale I'm using a Futaba PCM rec with the new 9C transmitter
the JR match boxes can be be ued with any rec or servo brand.
I checked the transmitter and went to the failsafe menu. all the control surfaces said " NOR" except for the throttle which said 20% ? I dont know what that means,, so I changed it to NOR as well. Ron

Hey Ron....Here's what I've found pertaining to my theory, and I'm emphasizing "theory", as it's definately not proven.

On page 43 of your 9C manual it's dealing with 2 types of fail-safe modes, one being standard, the other being what I was thinking could be the cause, and that's the "battery fail-safe".
Now....it's stating in there that the battery f/s mode is triggered when the flight-pack reads 3.8 volts or lower, and as I stated your plane will go to idle, or the value that you set it for. It also states if "nor" is set it will go to throttle total down w/trim centered. I would imagine the 20% that was set there was default setting. Think about this though, when you loose power, does it seem to go to low throttle, or fast idle, or about 20%?

What you might want to do is see if you can simulate the flight conditions without actually going to the air. Tie the plane up, have a buddy get behind it to stabalize, and run it like you are flying, and see if you can simulate, and recreate what your experincing in the air. Take voltage readings before, and about every 10 min or so, this might not be necessary, but you have it there on the ground anyways, and at least you'd know. This still might not tell you though, as the forces created by the moving airframe are extreme, and probably can't come close on the ground, but it may be worth a try, for your research.

Aside from that, take all your packs and give them a good cycle or 2, or even 3, and get some definate readings on the true capacity/voltage.

I've also copied a link here to the online manual section for Futaba's 9C, and there's a section to download supplements/technical updates.
http://www.futaba-rc.com/faq/faq-9c-q581.html

I really hope you get this worked out soon, this is one of the toughy's it seems. I've heard the 102 is an awesome engine. I own the BME50, and heard nothing but good about all of them. They are one awesome aerobatic engine.

I'm very interested to know now exactly what it could be....hmm....

I'm definately not any sort of authority on what you have going, but glad to share what I can.

And.........another thought after just reading your posts over again.
I'm wondering what the JRmatchboxes are doing to your voltage going to your reciever? What is the threshold that they deliver power. By that..I mean how much of a drain do the boxes actually allow ? I do know as servos are operated they are putting a load on a battery system, and servos will rob power from other sources that are not demanding it. I'm wondering if your matchboxes are allowing the power reaching your reciever to drop below the 3.8 volts.. I'm not saying it is a constant there, but if that voltage drops for a short time(milli-second?), could that be activating your battery-f/s mode.

What's JR's specs on these boxes? , and even more so, what's specs on JR's radios that might allow these to be more compatible there then with Futaba. I'm not saying that these are not compatible with Futaba, just areas to look at.

It might be interesting to see how it works without the matchboxes huh.

Have a look at all this, and get back to me in the morning.

http://www.futaba-rc.com/faq/faq-9z-q124.html

Also look at this, it applies to the 9Z, as well as 9C.

WOW thanks for taking the time to help me out with this Dale, I'll check on those things you mentioned,, One thing I know right now is the matchbox draws 12Ma as per the manual