DXB

No regrets at 4 hours into running the Surefly - too early to tell though. I'll keep this thread updated. As a natural pessimist, I haven't torn out my SOS system yet .

I'm confused as to what the Surefly really delivers in terms of differences in spark - they claim "higher energy". This means longer duration I think, which might help starting, or in far LOP operation- but otherwise should have no effect? The carb'd engines don't really get that lean before the power output among cylinders becomes too unbalanced, so C model owners might realize little benefit on the leaning front. What you say about the plug temp makes sense. If I see the same issue that @J0nathan225 does, I might try standard hotter (UREM40MRE) plugs at the Surefly positions rather than going to fine wires with a wider gap. I'm really curious to know how many hours it took for his two plugs to get so badly fouled, and how all his other plugs looked - did the other two Surefly driven plugs also have more deposits?

While we are on the topic, I don't really get why the Surefly would aid leaning on a carb'd engine (maybe I'm imagining the apparent benefit I report above). My understanding was that on an engine with balanced injectors, the timing advance reduces lean misfires. But on a carb'd engine, the roughness comes from different power outputs from each cylinder while leaning long before it gets too lean for combustion. I guess the timing advance could still give a little more power to a carb'd engine? I didn't see obvious evidence of that however....

Says battery pos terminal or positive battery input terminal to to the master solenoid - so both options are on same side?

Wow that’s crazy!! Are those lead deposits? Were they the 2 bottom plugs? Looks like you were running at a pretty typical power and mixture when it happened. Is that hot fouling or cold fouling? Would a different temp rating plug help? Did you talk to Surefly tech support? I’m curious what they’d say- they seem very responsive. Also did you check your non-Surefly driven plugs for deposits? Were they clean?

I’m not great at stuff that involves electrons, but I’m guessing it creates fewer points of failure for power to the surefly? Having it draw a little power when the master is off may be an undesirable side effect.

Fairly new TEMPEST UREM37BYs at whatever gap they come out of the box, I think 0.018 or so. I think there was a previous recommendation to use 0.032 but now their website says to use the standard gap

I did not notice anything unusual. I can’t say for sure since I did a couple of full power high speed taxis before takeoff because of the invasive maintenance, so I was starting from a hotter baseline. However I don’t see why it should be hotter at low altitudes in climb - it does not provide any additional timing advance at high MAPs

My left Bendix mag failed in flight when I was far from home, leaving me to fly home commercial. Rather than replace it with a conventional mag, I got it swapped it for a Surefly, which I had planned to do at annual in couple weeks anyway. Here's a PIREP: Install: - 4 hours labor seems pretty reasonable for just the mag alone (I paid more because of issues noted below) - It can go on either side, but put it on the left to derive the potential starting benefits. - It needs a manifold pressure input if you want variable advance timing - closest MAP input for me was from #4 cylinder head. - It needs a power input – taking it directly from the battery positive terminal itself was easiest for me, since it is right next to the left mag in the C model. - There is a fuse in the power lead provided with the mag. - Note there is a very slight continuous current draw from the Surefly even with the master off – they recommend a battery tender if the plane is sitting, so it’s perhaps not a good option for aircraft living on the ramp. -Bendix mag harness had to be changed to a Slick harness on the relevant side (extra $300 for parts and +2hrs labor) -Pitfall – NOBODY stocks half harnesses (for just one side), so order well in advance if you need to change a harness or you will have to pay for a full harness. -Pitfall – Know how your existing harness is routed before the install starts (mine weirdly had all the bottom plugs running off the left mag and all top plugs of the right). I would have left it the same way had I known, but the installer ended up rerouting the right harness to create the “correct” harness installation on both sides (another 2+ hours labor). Performance: -My first startup at about 50F temp without preheat on my carb’d engine was a snap. Temps <=50F usually take a bit more effort for me. -My mag drop at ground runup on left is slightly less than before, suggesting improved ignition on the left. -My first flight was at 7500 ft, WOT (MAP 22.7), 2500rpm. There should be some extra timing advance at this power. I did notice that I could lean to 8.5gph easily without roughness, whereas I can usually only go down to about 9gph under these conditions. The only problem I see so far: When switching from right (conventional mag) to left (Surefly) during a mag check, there is a slight but perceptible lag between turning the ignition key and the Surefly generating spark. This lag did not create an issue during standard ground runup. However, it caused a definite backfire during a subsequent in-flight mag check at the cruise power settings noted above with the engine maximally leaned out. I suspect this issue will preclude me from doing in flight mag checks, or at least force me to do them at lower power to avoid beating up my exhaust.

Wrap up to this story - I got the Surefly installed, and the bird is back home two weeks after I had to fly home commercial from Myrtle Beach. My first true breakdown experience, and a costly PITA all around. Thanks to @N201MKTurbo, @Andy95W, @carusoam, @Yetti and others for their insights. Chuck at Savvy Breakdown assistance (a free benefit of Global Insurance for me) was also hugely helpful in finding me maintenance help on a weekend away from home at a field with no shop. Savvy's subsequent management of the repair itself was not very impactful in my case but might have helped had it been unclear what had gone wrong or if the shop hadn't been communicative and responsive with me. In this regard, I think Deric at Executive HeliJet at KMYR did a good job and did not overcharge, particularly considering he was traveling to the ramp at a field 20 miles away to do the work. Also Surefly's customer service was great. Demand for these units is intense, and I had a SIM4N on backorder. They sent out a unit from their AOG stash to help me out. I will give a pirep on the Surefly in a separate thread, since lots of folks are considering this install....

I've thought about doing this many times! Stowe VT is a 2hr jaunt for me, and Mt. Pocono is trivial. Good snow conditions and good flying weather for the non FIKI piston single crowd do not go hand in hand however Then there's the worry about runway conditions at a small field after the kind of snow dump that would otherwise make me want to fire up the plane and go. The West Coast folks put us to shame though when it comes to skiing.. I'm sticking the plane in annual this morning instead and heading to Park City over the holidays...would love to take the M20C there instead of Delta, but it might not end well

Someone just put an annual on it, so that's good, assuming it's a real annual - it would be nice to know if it was a reputable shop that knows the Mooney airframe, or some pencil whip affair. I'm scared to ask...how many hours flown in the last 6mo? year? two years? If it's a decent amount, I'm then I'm hopeful. If it's next to nothing, then your pocketbook should be ready for an overhaul plus tons of other expensive effort before it can serve you reliably (even before you spend a dime upgrading the panel). If it has hardly flown much in 2 years or more, then you have to decide if you want an expensive project or you just want the fun flying with your wife to start soon. Nothing wrong with either - just depends on your priorities. Most severely underused planes that look like bargains when you buy them turn out to be anything but...

In this specific scenario, I'm not sure what those few additional words to explain "unable" would be. Presumably there was plenty of runway remaining and day vfr conditions. In our planes, a go around, even from the flare, should be no big deal. Perceived discourtesy from the controller in giving priority to #2 jet traffic after making the OP work hard to comply with previous instructions might make him irritated, but perhaps not "unable." And unless the controller violated the regs or gave a potentially hazardous instruction (not yet sure either is the case here), I don't know what the basis is to talk to the tower later.

Intuition would suggest the #2 landing traffic that is too close should go around. But is there any official guidance for controllers on this topic? If so does it incorporate considerations like the relative speed of the two aircraft? From this thread it seems like its pretty common for them to give priority to the jets.

Just saw this thread. It's actually kinda remarkable that >2/3 of voting Mooney aficionados served in the military! Even with some likely selection bias for people who served chosing to vote in the survey, it could easily be >50% in real life. It's a regret of mine to have not served - I'm kinda envious, but also proud to be in such company. Thank you all for your service!!

Before spraying, definitely seal off autopilot servos well by wrapping tightly in plastic before spraying and leave sealed for a couple days. Although they are quite safe for electronics, the lubricant action of these sprays can, for instance, wreak havoc on the clutch inside an STEC pitch servo. Subsequent attempts to fix can be expensive and exasperating. Ask me how I know .

And free bonuses offered by the site include the pointed critiques of weaknesses of the aircraft and the asking price from people not looking to buy

Do not push the owner to complete the annual - I see no reason why an owner should be willing to do an annual early, unless you are footing the bill. And if you are going pay for it, you might as well get it done at your shop on your terms. Note it is quite common to convert a successful prebuy into an annual. If you decide to buy the plane based on prebuy, it often makes good economic sense to complete the annual right then, even if it is a couple of months early. The plane will already be opened up for the prebuy, so there's little sense in paying to open it up again a couple months later.

Oddly, my mag drop has always been quite symmetric on a digital tach. Looking at the record of my mag check at runup done minutes before my left mag died in flight, the drop was precisely 140 on both sides. By the way, I really appreciate your sharing your seasoned perspective on this issue as well as other ones in the past.

One clarification here - what I have is a little different - Left mag was driving ALL the bottom plugs, not just the ones its side, and right mag was driving ALL the top plugs - per my reading very very few engines had this original setup, so it may have been an aberration setup at time of last overhaul? Is this still no big deal?

Ugh. Since the Surefly requires changing my left mag harness from Bendix to Slick, the A&P naturally used the markings for top vs. bottom on the new harness I ordered but found them to conflict with the existing harness on my right Bendix mag. So now a bunch of time is getting spent messing with the right mag and rerouting its harness. I wish I had known about this issue so I could have prevented the unnecessary rearranging - can't really blame the installer. I guess the only benefit here is finding out I've been misinterpreting my engine monitor all this time.

Thanks - yes it's still in CRE getting worked on by a local shop traveling out to the field. I took your advice and did all I could to see if they could replace the left with a Surefly. Because I already had a mag on backorder with the company, they were nice enough to go into their reserve AOG stash of SIM4Ns to help me out. Hopefully I can retrieve the plane this weekend. (BTW Surefly's customer service folks have been superb!) Now this issue with the harness is adding hours and leading to messing with the right mag, which comes off next week for IRAN anyway.

I'm aware that the left mag on my lycoming O-360-A1D is supposed to fire the top plug on #1 and #3 and the bottom plug on #2 and #4. What is the purpose of splitting it up top vs. bottom plug for each mag this way? I'm asking because during install of a Surefly mag, which requires changing out my Bendix harness for a Slick harness, the A&P noted that my harnesses were misrouted - i.e. the left mag was serving all the bottom plugs and the right mag serves all the top plugs. So now he has to mess with the right mag and reroute the right harness as well . I bet it's been this way since the engine was overhauled in 2000, and no one ever noticed. What adverse effect could this have had?

I thought it would be interesting to post the old advance curve (stolen off Beechtalk) just as an interesting reference, acknowledging it's not quite accurate. It does give a visual feel for the rpm/MP combinations where it can offer some extra timing advance.

Interesting I see nothing on the Surefly website about such a product currently available for experimental market. Was it a developmental prototype? I know the Emags have this feature and have been available for experimental for some time.