Read somewhere this mag wont work with horizon tachs there is a reverse polarity issue, also need a cylinder head temp guage per the stc if you want to take advantage of the advance timing feature. Still looks to be better then standard slick mags though at this time.

It went on easily, the extra spark really made a difference in starting on my IO-390 with fine wire plugs. Maybe its a bad thing to not have to learn the most perfect possible way to set up a hot start, but I sure like the fact that it will just start now. Like learning to do rolls in a Pitts, vs. a Citabriaâ?¦..you learn more technique and theory with the Citabria, but the Pitts is just easy and fun. I have it in fixed timing mode, but will try the advanced (variable) timing when I figure out how much the proprietary algorithm changes the timing. Im a bit paranoid about getting the CHTs up on climb out or high cruise. I think its an awesome replacement for an impulse coupled mag that is almost due for inspection/rebuild.

Installation took some additional time as we had to use the alternate positioning of the gear onto the SIM shaft to enable engine timing. Initial starting was about one full turn of the propeller. Fastest start in over 10 years of ownership!

My partner and I recently replaced the Left (Impulse) magneto in our 172N with a 0360 Lycoming and twin Slick magnetos. The installation instructions were clear, accurate, and the results are essentially as advertised: smoother idle, easier starting (especially hot-starts), and a notably smaller drop in rpm during run-up. However, it was during the run-up that an interesting trait of the electronic magneto made itself known: During the run-up, when rotating the ignition switch from R to L, there is a brief but distinct POP apparently from the exhaust, similar to a slight backfire. The POP is considerably more pronounced when performing a magneto check in lean cruise, and probably such checks should be avoided. The POP happens every time the switch rotates from R to L and at no other times. Its obvious the anomaly occurs the instant the L mag is turned on during the R to L motion of the ignition switch. The actual POP, I suspect, is due to the L magneto initially providing a retarded (25 degrees from the normal advanced setting) spark because it doesnt yet realize the engine is running. The retarded spark ignites an overly rich mixture which is still burning by the time the exhaust valve opens, hence the POP. Again, probably not an issue under normal run-ups, but at altitude under load Id have some concern over the exhaust system. I spoke with Bill at SureFly about this and discovered Im not the first to have noted the issue. SureFly suspects the cause is due to the design of the ignition switch along with the 100 milliseconds it takes the SureFly to actually produce a spark after it is ungrounded. Their thought is this delay results in an instant between R and L during which neither magneto is operating, thus causing excess fuel to accumulate in the cylinder. The L magneto then ignites that rich mixture with the POP being the still burning fuel when the exhaust valve opens. SureFly is currently attempting to get FAA approval for shortening that time from 100 milliseconds to 1 millisecond. Perhaps that will address the problem. That said, when rotating a perfectly good ignition switch from R to L, there is no point where both magnetos are grounded. In fact, the L magneto becomes ungrounded (turns on) well before the R magneto is grounded (turned off).

Long story, so here goes: My plane has a 24V battery in the tailcone, and the Surefly has to be connected to the battery side of the battery contactor for the STC to be valid for the installation. (This is because if the battery contactor fails and you lose the power bus, the Surefly still runs the engine off the battery) As 24V AGM batteries are in the $700 class nowadays and there is a (albeit small) leakage current on the Surefly when the engine isnt running, and leaking current kills batteries, I heeded the advice from Skip Koss from Concorde and put in a fuse holder in the instrument panel that would let me disconnect the Surefly power from within the cabin to shut off the power when I wasnt flying. The trouble is that would leave an unfused length of wire from the battery to the instrument panel. So to ameliorate that, I put a 15 A fuse in the fuse holder in the tail and left the 10A fuse in the panel. The Surefly was then installed at the annual, and I left in the original plugs and harness, even though Surefly recommends replacing both the plugs and harness when installing the Surefly.. Ran great, seemed to climb better, and I definitely got book speeds in no-wind conditions in cruise. But there was an oddity: during climb between 8500 to 10,500 the engine would balk unless I used full rich mixture. Huh. Weird. Well, they DID say to change the plugs and the harness. So I changed the plugs to an New-Old-Stock of Autolite UREM38Es I bought 16 years ago when they were $9 each. Well, that made matters worse. Now the engine was skipping randomly, losing 100 to 150 RPM, then surging. Happened in climb, cruise, and descent, once even when I was on takeoff and only 50 feet off the ground. Very sphincter-puckering moment, there. Egads, was it the plugs? Harness? I thought maybe there was some momentary bridging of the electrode gap, so I widened the plug gap. For one flight that seemed to work fine, but the intermittency came back a week later. Gads. So I changed the harness with a new Champion (the old one was the Aero-Lite that I put on 9 years ago) Nope, same problem where a full-power runup on the Surefly magneto alone would have a 200 to 300 RPM drop in the runup, then seem to work fine, and Id see 100 RPM drops in cruise when both mags were on, then surge again when the ignition kicked back on. An in-flight mag check saw a 200 to 300 RPM drop on the Surefly alone, and running fine (no RPM drop) on the right magneto. On two flights I had 6 misfires between initial climb and turning to the downwind leg, so I just came back to the airport on the right mag. While all this was going on I called the Surefly tech line many times, and Bill and Tom were paragons of patience and good advice. I was all set to pull the mag and send it back to verify it was working, and Bill convinced me to do a pull test on all the electrical connections from the battery to the Surefly, check the engine ground strap, and to check the P-lead grounding on all ignition switch positions with an ohmmeter. (The Surefly installation LED blinks the code for the advance timing settings whenever power is interrupted, so if an intermittent occurs in the power wire, it would show up on the LED). So I removed the 10A fuse from the instrument panel, moved it to the fuse in the tail cone, and re-did all the crimp connections for the power wire, then yanked each lead while watching the LED. Another odd thing happened when I pulled the 15A fuse out of the inline fuse holder in the tail cone, namely, the fuse just dribbled out, Normally theres a spring that holds a small preload force on the fuse to ensure contact, but it seemed like there was little or no force on the fuse when I pulled the 15A fuse out. There WAS spring force on it when I reinstalled the 10A fuse, so its possible the brad inside the fuse holder cocked a bit when I put in the 15A fuse just enough to keep the preload off of the fuse, thus making and intermittent/poor electrical connection. Subsequent pull test on the wires never got the LED to blink, so that confirmed the power was rock-solid to the Surefly. The first runup had a bit of a stumble, but seemed to clear up with a high speed runup (like a typical fouled plug) and next test flight ran perfectly. The hiccup where I needed full rich mixture from 8500 to 10,500 was now gone. and I got up to 12,500 with relative ease. So, upshot after this long story: Yes, it works. According to Bill at Surefly, the spark advance starts when manifold pressure falls below 24 inches of MP, so power wont fall off with altitude as much as it does with the constant-timed magnetos, so rate-of-climb will be improved and, in my case, I get actual published book speeds even though my plane was in a major accident in its youth. BUT: make sure you get it installed right! Sometimes even the little things can bite you on the rump and affect how it all works. Mine seems to be running fine so far. Hopefully your installation will learn form mine and will go a lot smoother. Best of luck to all. Happy flying.

Well made product, simple to install and easy to set the engine timing. Engine performance seems to be better and smoother. Like the feature to use the existing ignition harness and spark plugs.

Iâ??ve flown with electric ignition in a Long-EZ for years and was wondering when it would show up for certified aircraft? Had a mag fail itâ??s 500 hour inspection and it was less expensive to go this route rather than repair. Surefly is super easy to install, about as simple as a traditional mag. I have an EI tach and it required removing the current resistor and replacing it with an 18 ohm version. Tech support was friendly and helpful! No wonder Lycoming is picking up this product.

I like it! Ran rough in the beginning because harness Springs needed a little stretching to make contact with the Sim, but once everything is working as it should itâ??s a great product,, the plane runs as good on it alone as it does on both regular mags ð??ð??ð??

*not paid by surefly at all, but rave to everyone about this. 10 Stars! Surefly will put slick and bendix out of business. Have a well kept Cherokee 180 had a hard time starting hot. Mags only had 200hrs, replaced left with this one and BAM! starts every time very easy! No matter how hot it is. Runs smoother, gets better fuel economy and has more power. Cruises about 5kts faster at a lower fuel burn. ~115kts @ 7.5gph now vs 110kts @8.5gph Best money Ive ever spent on the plane.