FX3: intermittent zero amps, spiking oil temp, strobes tripping off

[cavok84]

I took delivery of my FX-3 in late March 2023 after the factory accomplished the 40-hour fly-off for me. Since then, I’ve put around 190 hours on the plane, the majority of which being comprised of sandbar and riverbed flying with some extended three to four-hour trips mixed in there.

The plane has been great, and it’s only somewhat recently that I’ve acquired a collection of issues that has me completely stumped. Initially, I thought these were minor isolated issues, but I looked at my g3x data recently, and now I’m concerned I may have a more significant problem.
I live and fly the plane in the southeast, so hot and humid, but it’s always been hangar kept.

Timeline
1. July ‘23- Oil Temp had always remained around 190 degrees; however, at the beginning of a three-hour flight, the oil temp oscillated fairly quickly between 190-225, with no change to oil pressure. I land and reseat the oil temp prope connections. After taking off again, the temp is running high but within limits (maintaining 195-210), about 10-15 degrees above expected but rapid oscillations stop.

2. The mixture cable spring that gives the knob detents when pulling out or pushing in breaks. The mixture knob isn’t freely moving, but it makes precision settings difficult when bumping around.

3. Nov ’23- Condition Inspection goes well. The oil and filter have been changed every 30-40 hours of flying with no issues noted.

4. March-April ’24- I begin noticing that my Strobe switch isn’t on mid-flight. Initially, I thought I was forgetting to turn it on, but it was around this time that I first saw the Strobe switch trip off during climb out. Very rarely, I will notice a brief dip to zero amps, followed by a rapid recovery of amperage (maybe a second at zero, if that).

5. Apr 23 ‘24- Due to the oil temp showing 15 degrees higher than ambient when turning on the IBBS (cold aircraft). I order a new oil temp sensor from Cub Crafters and have it installed by one of their Service Center mechanics. We also perform a thorough inspection of the aircraft and replace the mixture cable (Erroneously high oil temp reading is fixed).

6. Apr 23rd thru 30th- over the course of eight hours or so of flying, everything goes well. Oil Temp is back to 185-190, no oscillations; however, I begin to see the Strobe switch trip off more frequently. This doesn’t happen every flight, nor does it always happen more than once per flight; its highly variable.
I can’t correlate the behavior to anything in particular. It seems to happen in the pattern more often (high AOA, high vibration, frequent movement of throttle, etc.).
*However, I’ve seen the amp behavior with the Strobe switch off, and I’ve seen the Strobes trip without noticing amps dropping. (I’ll confirm this today)

7. April 30th, '24- During my last flight, shortly after liftoff, Oil Temp skyrockets, jumping from 190 to well past the redline in rapid oscillations. 190…280…190…300… blank….260….blank… etc. After completing the flight, the temp shows 195 at shutdown. Strobes didn’t trip.
The day after the flight, I do a runup. Temp shows 150 at a warm idle; however—above 1200rpm, the oil temp resumes the behavior, immediately jumping to the red and returning to expected normal (150 in this case) at low rpm.

8. I reviewed my flight data over the past couple of months) and noticed that amps typically hold at 2, sometimes 1, but occasionally hit zero (after zero, amps jump to 2 but sometimes 5…4….3…2). Looking further into the past, it seems this started quite a while ago (at least Jan), however occurrences are rare.

****
-Overall, I only saw the amp issue a few times on the g3x, probably because it only lasts a second or so, and most of my flying is eyes outside.
-My data logs at home for review are incomplete, and I’ll have more info once I download a complete history (e.g., when the amp drop began, changes to its frequency, what was happening at the time).
****

Considerations
Presently, I have a second, brand new oil temp sensor from CC in the event there actually is a problem with the sensor itself (this will be the second oil temp sensor replacement), but the amps hitting zero and Strobe tripping worry me.
-Could the Strobe wiring be shorting, causing the switch to trip off and interrupting alternator output (some sort of system surge to which the alternator output reacts)?
-Or is it more likely that I have an alternator issue which is shedding the Strobes?
-Or are they completely unrelated?
-Does the oil temp issue imply a greater electrical system problem?

I apologize for the wall of text, but I am a first-time aircraft owner, brand new to tailwheel and backcountry flying.
Tomorrow, I can follow up with some data logs if anyone has any ideas.

Thanks!


Cavok