I have a great planes 300 1.60. I have installed a fuji BT-50ei on it with futaba fm receiver, 1 futaba 3004 for throttle; ailerons, elevators 3010 and rudder hitech high torque(forgot #). Flew the plane fine 5 times but now have interference with engine running. receiver mounted 2 feet from ign. module along with throttle servo(plastic connecting rod attached to throttle). I hope somebody has suggestions on how to fix this.

Start by confirming that you are using a resistor plug together with a shielded plug lead. The resistor plug should contain an "R" in it's number.
Not only should the receiver be kept at a distance from the ignition, but also all associated receiver wiring. That means battery, switch harness, charge connector, and all servo wiring. Also check to see that all your grounds are secure.

> Jim

The spark plug is resistor type,the switches are about 10 inches apart. I will check all my grounds. thanks

Your RX switch and your Ignition switch need to be MORE than 10" apart.

I had the same problem with a G-62 and C&H ignition.

Your ignition battery. Your ignition switch. Your ignition module. Your charge leads for the ignition system. All this stuff needs to be as far away from the RX stuff as possible. Farther away than you think.

My problem was as follows:

Igniton switch was too close to RX switch, RX, and RX battery.

I moved my RX switch, RX battery, and the RX 18 inches away from EVERYTHING related to the ignition. Problem solved.

Try running the RX antenna out the OPPOSITE side of the plane from the switches. ALL my switches are on the right side of the plane and my RX antenna runs out the left side and down the side of the fuse--untill it hits the root section of the horizontal stab. Then the antenna makes a sharp bend and runs right along the LE of the left side stabilizer. I've used some covering to iron on small strips over the antenna to keep it in place along the LE of the stabilizer.

Making a sharp bend in the LAST 10" or even up to 1/3 the overall length of the antenna wire will help your reception in some situations. If you run the antenna INSIDE the fuse----in a tube---and run it straight back to the tail--------you haven't got a very big "profile" or "cross-section" of the antenna for your radio waves to look at when your on final.

Point your index finger directly at your eyes. Right at your nose- so that you almost gotta look cross-eyed to see the index finger. Not very big, is it? Thats about how your RX sees the radio waves that are transmitted to the plane on final.

Now turn your finger 90degrees to the left or right side and look at it. Lots bigger isn't it??

Run the antenna on the outside of the fuse. and when it gets to the tail-- either run it up the vertical fin or along the LE of the horiz. stabilizer. Cut little strips of covering about 1/2" wide and 1" long. Iron one side of the covering on and then lay the antenna down and iron on the other end of the covering. Shrink to fit. It works great for securing the antenna to any covered surface, and it's not very noticable. Helps my reception on final approach. I used to get a glitch every time I came in on final. It would twitch the rudder left and burp the throttle. Not fun when your 6' off the deck and going slow.

The new route for my antenna and also seperating all the RX from the ignition made a HUGE difference. I can do slow touch and goes now with confidence.

fought this same problem with my funky 50 and had to put twisted aileron ext wires in the wing to stop it.but then the engine took a crap and i junked the piece of and put a 3w 60 in it.boy wish i had bought that engine in the first place,

.

Add a Bosch Shielded cap from CH Electronics

Thanks RCPILET, sounds like you have alot of experience. I will try all off your suggestions. I am a beginner at this and I need all the help I can get. Thanks

Consider this- you stand on the ground and transmit a signal that you expect to be received by your airplane that is up to 1/2 mile away. Now if your engine is emitting interference in the frequency range of your receiver how far do you suppose you would have to get away from the emitter in order to not hear it? That spark is at least as powerful transmitter as your transmitter is. Your only hope is to shield the spark and the wires to it. Hanging the receiver on the tail with curleycues in the antenna will not help.
Find the source of the interference and fix it. If it worked OK in the begining something must have came loose.
Try what tkg suggests. He has been building spark systems for years and knows what to do to shield it.

The hole "you have to keep everthing at least 12" from everything else" ideology just isn't true. Like dirtybird said, what you need to do is find the source of the radio noise and fix it. I have my ignition switch and ignition battery about 4" from my receiver switch and receiver battery (they are mounted to the fuselage sides directly across from each other) in my Laser with Brison 3.2 and have no interference issues. I highly recommend the Bosch shielded cap as tkg suggests. It does a great job suppressing electrical noise. Good luck!

Where can I get the bosch sheilded cap. Is it just the end of the spark plug wire(boot)?

Yep, that's all it is. I don't work well with electrical components so I send my ignitions to [link=http://www.ch-ignitions.com]C.H. Ignitions[/link] and have them do the work. Thay have the caps there if you want to do it yourself.

It is possible to find Bosch spark plug end at car junk yards. Look on import cars or trucks.

I'm just reporting my personal experience. My stuff was a SOLID 10" away to start and I had BIG problems.

I DECIDED go by the old theory of "Keep it all 12" away"-----and my problems went away faster than a fart in a hurricane.

I am using a Bosch sheilded cap. It's been on the ignition system from the very begining. I even tried to sheild the spark plug WIRE initially. You can buy coaxial cable at Radio Shack. It's big enough in diameter that you can slice it lengthwise down the side and pull the wires out of the center. What your left with is the external shielding. It's big enough to wrap around the plug wire. I wrapped it around the plug wire and then cut a few pieces of 3/8" heat shrink tubing and shrinked the sheidling over my plug lead. Had to remove the plug cap first, but it's easy to solder off and then solder it back on.

Didn't make a bit of difference untill I moved everything 18" away.

The shielding needs to be done by someone that knows how to do it.

Have not done a Fuji with EI so don't know how easy/hard to do. Is the plug wire, wire or resistor lead??
On the magneto engines its a snap.
www.ch-ignitions.com

First, send the ignition system to Terry. It's probably the cap. There are few who can take care of your ignition problems as well as he can.

With regard to the distance thing. I set just about all my gassers up pretty close to the same. First, I don't re-use extensions from another plane. Same with switches. I sell the used stuff to the glow fuel junkies when I'm done with them.

The flight battery and the ignition battery will often end up within two inches of each other in 30% and under planes. When that happens it means they are within 3 to 6 inches of the engine and ignition module. The ignition switch will usually be within 6" of the batteries. Both switches. The receiver has been known to reside within 8 inches of everything else.

I also always use a metal rod with ball joints on both ends for the throttle rod. The only plastic on the rod is what holds the balls in the fixture. None of the servo leads and extensions are ever twisted, but they are always good ones. I always use a shielded cap.

Guess what, no glitches with a ppm receiver. Range check distances are rarely less than 200 feet, antenna collapsed. I would think that distance would be eliminated from the interference equation after all that.

Personal opinion is that ignition/engine interference is usually caused by sloppy workmanship, inattention, or lack of knowledge. Sometimes all of the three. Using the wrong type of part for the job often ends up the culprit, too. Other times it will be caused by someone trying to go cheap in an expensive arena. Take the time to do it right the first time. If the cost is getting too high, fly something else while you build up a little capital rather than shortcut the project. Think it through and look for areas where a loose connection or metal rattle could pop up. If you locate something that seems like it could, it will, so correct it before it happens.

I would much rather see a plane on the bench for a little bit longer than as a pile of broken dreams on the ground.

If all the above sounded harsh, please forgive if you will. It wasn't meant to be, just unfettered.

Very interesting Silversurfer. Just be careful - there might be those that resent your exploding their cherished myths

The word "myths" speaks volumns. Thanks for the heads up

It's just that these same problems keep cropping up all the time, and the solution seems to be most often found in an equipment deficiency. In the earlier days of gas engines and giant scale, the available equipment was not nearly the quality of what we have today. The ignition systems were those that were found on the lawnmower the engine was originally installed on. The receivers were all manufactured and tuned to much lower standards than we now have. Hardware for connections were often loose and vibration prone due to different design standards, etc.

Sure, I agree completely that you can purchase new, off the shelf, products that from time to time have a defect, but it really doesn't happen all that often. Design defects are another matter altogether. But again, the interference problem will still most often be found in a connector that has been pulled a little too hard, a battery, receiver, or servo that has been through a crash or two, and not sent in for a check up, a switch or two that has been on upteen different aircraft, and so on.

Failure to adaquately secure nuts and bolts against vibration can be quite a little bugger as well. Ask TKG how often an "ignition problem" has been sent to the shop only to find nothing wrong with it, and later discovered to be a loose engine or muffler mount. With the exception of engines using a CM6 or smaller plugs, the use of a non-resistor plug that someone purchased cheap at the local hardware store, or took out of their weedeater, has caused more grief that a person can imagine. Look for an "R" in the part number.

The same problems occur with an engine/ignition combination that wasn't properly grounded, or the ground wire (if it has one) was loose or never connected. That's where the use of the shielded Bosch cap has worked out so well. It's design darn near eliminates the interference problem. But they do cost a little more so some go with the lesser quality plug wire and cap. Or worse, the unqualified will open up the ignition system in the attempt to convert the plug wire themselves.

The other side of the situation is where an engine and radio system had been operating properly and well, but suddenly becomes a problem. The answer will be found in what had changed from then to now. Was the plug removed and dropped, cracking the ceramic? Was the plug wire pulled off the plug with too much force, pulling it out of the ignition/magneto connection? Has the plug wire been cut by the cowl fitting too close? Has something loosened up causing a mechanical glitch? Is the engine running rough or missing all of a sudden due to an excessively rich oil mix? Is a digital servo getting ready to say goodbye? What about that old battery you've been using in the ignition (if it's not a magneto), is it taking and holding a full charge? Worse, are you trying to get too many flights on an ignition battery between charges? Did the isolation motor mounts that were used shake the plug wire off the engine?

Anyway, the above was meant to be informative and not critical. Looking at it all and I can easily understand why it would be viewed that way. I have to admit that I've been a little grumpy lately, which I'm sure was reflected in my prose[] Mea Culpa, and I apologise to those that were offended. But hopefully, some of it all helped.


Pat

hi ptgarcia, I am also quite new in gas. Is it also necessary to make some place between the ignition switch and the ignition battery? Or it was a mistake, what you really wanted to say was between the RX switch and Ign battery?

Sorry Redrata, I screwed up. What I meant to say is "I have my ignition switch and ignition battery about 4" from my receiver switch and receiver battery (they are mounted to the fuselage sides directly across from each other)"