SPE 40 ignition problems
 

I have been flying the engine it a Gere Sport all summer. Last weekend I went to an event and the first day, it ran like normal and I was having a blast. Well, until the solder job on the muffler failed. So I removed the muffler, went to a local club members home and we reworked the solder/weld joint and supported it with a JB Weld like product from the commercial world.

The next day dawned a bit colder, but I was in the air again and noticed the throttle acting real funny. I landed and checked things out, refueled, and went back up. Everyone was astounded at the fact that the throttle was cycling between idle and wide open all the time, so after a short flight, I decided it was time to disprove all the naysayers and do some touch and goes. On the second approach, the engine quit so I landed.

On further investigation it was noted that the throttle servo was acting like a windshield wiper when the engine was at full throttle. If the engine was not running, it was as solid as a rock. We changed the servo, the hook up, the receiver, the transmitter in an attempt at correcting the problem. Each time a change was implemented, I restarted the engine and went to full throttle. Each and every time the throttle servo (which did get moved further back in the aircraft) windshield wipered.

It seems that the SPE 40 has a fairly large air gap between the magnet and the pickup, so I called C&H and he wants me to send him the engine because he thinks he has parts to fix it. Estimated costs are between $125 and $150, probably plus shipping which really is fair given that the SPE 26 part is around $28 and the single ignition systems about $78.

Right now I have 3 or 4 engines that need to be shipped somewhere to get fixed so adding this to the 'fix it' list is a real bummer.

Does anyone have an unused SPE ignition module?

Is this engine worth fixing or should I search for a replacement?



Thanks.

Sounds more like the plug cap is not all the way down on the spark plug, 99% of the time this is what causes RF on servos when engines are running.

And yes it will do it with 2.4 systems.

Milton

Oh, I understand that most know more than I would hope to but that was one of the very first things we checked because I really like simple answers. :(

To be a little bit more explicit, I have (my buddy and I build) a totally electronically free throttle connection to the radio using fiber optic lines and putting the throttle servo near the engine and sharing the ignition module battery pack. This was originally designed during the days of 72mHz and has never failed. After checking the plug, that was the very first thing we took out of the equation by going to a direct connection through an extension on the extremely remote chance (maybe 1 out of 10,000,000) that something was awry there.

The second thing tested was changing out the servo for a new one and we tried that with and without the throttle circuit isolator. We never changed the servo back to the original. The third thing we tried was moving the servo so that it was further away from the spark stuff. We also tried that with and without the throttle isolator. The fourth thing we tried was changing the receiver on the basis that maybe somehow that is where the problem was even though the elevator and rudder servos were closer to the engine than the receiver (see, I said stupid). The fifth thing we tried was borrowing someone else's transmitter and binding it to the installed receiver.

In ALL cases when the engine was not running, everything was fine at all throttle settings. When the engine was running at low throttle settings, things seemed fine. However in each and every single case when the throttle was advanced to max, the throttle servo in use across whatever circuit that was in use, with whatever receiver or transmitter that was in use, windshield wipered.

Jim, you state that everything was fine until the muffler broke loose. Is there any way when the muffler came loose it could have damaged the plug wire/shielding?

That could be a bad/loose connection about anywhere causing that. Battery, switch harness, anything. I don't like throwing parts at a problem, but in this case, it may be justified?

You don't have to send it anywhere. Just buy any Hall effect sensor type ignition and install it yourself. I have the same engine and I am running it on the FTL replacement ignition that Hobby King sells. It comes with a 14mm plug cap. I choose it because it was made by RCexel, which I like and trust.
All my Melody ignitions failed. But I did get several years use out of a couple of them.
You might want to get an ignition and a new hall sensor in one deal with a matching plug cap. I think I usually send people to Milton (rcextremepower). He's here on this site and very helpful. He used to sell RCexel but now carries the new and improved version. Here is his info

Contact [email protected]
Team RCeXtremePower.com

No, I am very careful to install my stuff so it stays clear of the muffler and/or stacks. I have noticed that melted electronics seem to let the magic smoke out. In this case, the exhaust stack from the can broke loose but it was strapped to the fuselage so it went exactly nowhere. The only 'problem' was the messy exhaust oils and rich mixture. What I did not report (not being perfect it never occurred to me) is that the windshield wiper activity did get worse as the testing went on. That is why the aircraft was hangared for the balance of the weekend and is on the 'fix it' list.

All connections were checked when the plug cap was checked. I was 'playing' with some pros so just about everything was choreographed to be successful by all of us and cross checked.

Kmeyers, right now I am contemplating pulling the engine and shipping it to C&H versus buying one of those 40 cc kit engines (always investigate all the alternatives, some of them have to be bad!).

Having already talked to him, I would rather stay there as I have several ignitions from C&H and I want them to stay around for a while. I thought the RCXEL ignition is what Bill C. moved to in the final years he was running the operation. Or so I was told when questioning how to use the tester for both types of ignition systems that I already own.

The only problem with a conversion (as I see it) is only the wide gap between the magnet and the Hall sensor. How did you handle that? How did you convert the connection from the sensor to the ignition system?

Jim,

Did you ever find a replacement module?

No, but thank you very much for following up and asking.

I have a spare RCXEL module but did not test it as the connector to the Hall sensor is different and I am loathe to fix what is not broken (in other words modify the connection on a brand new module). None of the ignition systems (some 3W, C&H, RCXEL, and an old Synchro Spark) I have has as large an air a gap at the sensor as this engine had, so I shipped it to Adrian for conversion to the C&H system. I figured that since he fiddles with this stuff all the time, he is probably more knowledgeable than I am. I tend to keep my word and I already said I would ship the engine to him unless I found a quick fix. I am sure that [email protected] of Team RCeXtremePower.com is probably just as good, but I had already called C&H.

Right now I am trying to figure out why I have a brand new spare RCXEL system in a drawer in the shop. Everything else is running just fine and I would rather get a newer engine than convert an old (read that as heavy) one.

Jim,

The reason I asked is that I have an SPE/Melody ignition that came off an SPE 43 that I no longer use, The sensor is gone off the end of the lead. It would need to be replaced. Are you interested?

Darn. I would have been extremely interested before I sent the engine in. Now it will just be a good back up as I pulled the sensor before I shipped the engine. PM me details please.

How about $20, shipped?

Sent you a note.