Next will check the wiring inside the shielding between the stator and the modules. I'm no genius on Rotax, but my first thought was that if both modules had failed to spark, then it had to be something common to both. Now starting easily on A side old module alone. I got my new gearbox parts today. . But that doesn't really explain why it would run above 2500pm but not below, and then a few moments later run fine right down to idle.
That Rotax is a bargain. I do electronics for a day job and been doing it long enough to know that they are all smoke driven and when smoke escapes they dont go anymore. There are airframe issues and there are engine issues. Sure be good to get flying again! Sure wish I could find something broken and just replace it. I've had one of them fail on a stationary motor once. You just give the prop a flick or get some more power for the battery, and it will start - basically to spark! Figure 5 on page 10 shows this grounding method.
The clues: But thinking about it, they probably didn't fail at the same time. Resistance measurements of coils, pickups and charging coils, as per Heavy Maintenance Manual, are all correct. But now that I've tried one of the suspect modules on another aircraft and find no spark there as well, I think it's pretty much focused on the module itself now. Maj - That sounds very much like it fits the clues. Unfortunatly it did turn out to be dead stator for some reason.
But on further reading you seem to have covered that. If there is a change, sus- pect the carburetors. Wal called it a 'lazy' stator. This Directive requires the cable lug to be inspected for correct installation. This was done because that airframe was designed to mount the boat anchor weight certified motors.
Moving weight forward was needed to keep in balance. This particular problem has plagued me for several years - very difficult starting that has got slowly worse with time. . And it was gradual, there's been several times in the last weeks that it was difficult to start, but finally did and then ran well with good mag checks at 3000, so the problem was blamed on flooding. And may do it intermittently as well.
The wires coming out of the alternator are covered with a fairly robust shield. That's just the sort of thing that could do the damage. Easier to just replace than overhaul, I guess. I did my 701 wiring rather loosley, and used nylon cable ties to keep wires in order and out of harms way. Recently had a similiar problem on an 80hp on a Pegasus trike. Not very technical, but then these problems are sometimes really simple.
These clues don't help narrow the mystery, but make it even more confusing. The Soft Start Module helps overcome the problems caused by these short falls. How do you test that without replacing it??? If it's going to be grounded inside as well, there probably should be a resistor placed in the connection. Yesterday I was doing lots of flight testing of reflexed flaperon settings, so many shut-downs and start-ups. I have adopted the simple scheme. Since this summer, I've been having an issue with vibrations in the 2000-3000 rpm range. After about one minute of running, 'A' side decided to run well right down to 1400rpm.
Ignition system With the new module on A side, it starts every time - so far. I just did a 48hr cross-country trip with no problems. Both have been modified with centrifugal clutches. Prior to installation of an electronic module on an engine. Ready to run with all the accessories it costs quite a bit less than a new 582!! It was so lazy it was dead!!. Most of your gauges will have a + 12v connection to power them and a ground to go to the airframe, and a wire out to the sender which is usually grounded to the engine or airframe-for the fuel senders.
I don't really like the setup, but it is far more trouble than worth to reengineer the whole thing. Once running it wouldn't run on the A side at lower revs again, but after less than minute of running then it would run on A right down to idle, and restart again only on A. This is the reason for the odd style oil tank mounting. A single carb, auto tranny, 94 station wagon is probably the best for planes. So I placed the Soft Start module on the B side, and always start on that side now in order to keep an eye on that module.