pfactor

Thanks so much for joining the forum and participating, Andy. I've had my Aspen in my Mooney for 8 years and 1300 flight hours with absolutely no troubles. I had the synthetic vision option with the original unit, but didn't use it all the time due to low frame rates. I just exchanged my old unit for a Pro Max at the start of December 2019, and was really happy with the upgrade. The display is brighter and crisper, and I really like the larger fonts that are easier to read. And the faster processor made it so that I can use synthetic vision all the time. The new Pro Max unit didn't give me any problems for the first 26 hours. Just this weekend, the unit rebooted twice in during a 2.2 hour flight. I'll contact my dealer for help, and I've also got video of the Aspen during the flight if that would help you diagnose things. Contact me directly if you'd like to see that. I had one more 1.6 hour flight after the problematic one above and there were no issues on that flight. Phil

I used to have lots of hot start problems in my 1977 M20J, and asked Mark Rouch at Top Gun for advice. He said if it's been more than 1 hour, use the cold start procedure from the POH. That works like a charm for me.

Here's an update from a couple of years after fixing the broken wire in the magneto secondary coil and switching to Tempest fine wire spark plugs. I have had zero starting problems since doing those things. Hot starts, cold starts, warm starts. It's all great now.

Success! It was pretty much what bradp said above. The magneto overhaul shop found and fixed a break in the secondary coil (they did this for free, since they had just recently done the overhaul). They said that would cause poor spark at low RPMs for start, but would be ok at higher RPMs after starting. Now that's fixed and I also installed Tempest fine wire spark plugs. The plane started right up for my mechanic today. Oh, and we decided not to install the Slick Start. I'm looking forward to flying tomorrow!

What's this? I tried searching for it and couldn't find SI 1625. Do you have a link? I'd like to get 3 knots back. The shop that overhauled the magnetos last time said they would inspect and repair for free (since it's been less than a year since mag overhaul). But I take your point -- it may not even be worth doing that, and just pre-emptively switch over to Bendix mags if Slicks can have the terrible failure modes you described.

When I ordered the factory remanufactured engine in 2007, I don't think I was given a choice about what type of mags to get. So if Lycoming normally ships with Slick mags, that's what I've got. I'm not actually sure but I'll find out when I talk to my mechanic tomorrow. Based on this thread, here's my current plan. 1) Change out the spark plugs for Tempest ones. I haven't decided on massive or fine wire yet. 2) Send the mags back to the overhaul shop for inspection/repair. Test with a known good mag while waiting for that. 3) See if http://www.mooney.com/en/si/M20-59A.pdf was previously done, and if so undo it for my two-mag engine. 4) Check that the fuel drain tubes are not blocked. 5) Maybe install a SlickStart Thanks to everyone for the suggestions and help!

I think I'm going to have to decide between spending around the same amount of money for either a SlickStart or new Tempest fine wires. I'm leaning towards the new spark plugs since I haven't seen any support for the SlickStart idea. Oh, and the shop that overhauled the magnetos last year says they'll re-inspect and fix them for free. So we're going to do that as well.

Good idea. This isn't a conclusive indication, but when I deliberately flooded the engine to try to start, I had fuel coming out the drain tubes (as I was pushing the plane back in after giving up). I was wondering if there could be a problem like too much fuel at start time causing the behavior we're seeing. I'll ask the mechanic to check out the drain tubes.

I think I've only got the impulse coupling on the left mag. I found this SI M20-59, but that's about the landing gear. Did you mean a different one?

I have an impulse coupling. I updated the original post with that now.

I've got a 1977 J model with a Lycoming IO-360-A3B6. The other day I couldn't get it to cold start. Those have never been a problem for me. The prop turned, but there was no sputter or any a hint of combustion. I deliberately flooded the engine and tried a flood start, same deal -- no sputter. My local mechanic took a look, and couldn't figure out what was wrong. The spark plugs are firing, the P-lead is good, he checked the ignition switch and even tried bypassing the switch to see if that would help. Finally he put everything back together and gave it one last try and managed to get it started. He said the engine ran poorly after that start, but it may have had too much fuel after all the previous attempts. But he did get it started, and he told me to try it and see it would start for me. Last Saturday, it started immediately on my first cold start attempt. The runup was perfect, and engine operation was smooth for the 1.5 hour flight, with a good in-flight mag check. Went back to fly last Sunday and I was back to the original no start problem. No sputters, nothing. Flooded start didn't work either. Grrrrrr! So it's back in the shop and my mechanic is stumped. He says he's checked everything he can think of. The spark plugs are firing, the timing is within 2 degrees (he's going to adjust that). The ignition switch seems to work correctly, and bypassing it doesn't help. He mentioned that he's a big fan of SlickStart and has one in his airplane. He's not positive it will fix my problem, but it could help. I've seen mixed reviews in searching. I've been reading some threads that mention switching to Tempest fine wire plugs has helped some people with starting issues. I'm wondering if I should try those over the SlickStart. Other items of note: The magnetos were overhauled last November at annual. I've flown about 60 hours since then. The engine is a factory reman with about 1000 hours on it The spark plugs are REM38E (looking at my logbook -- it doesn't say the brand, but I think they are Champion). They have about 600 hours on them. My mechanic says they tested good. I don't know if he's tested the resistance (I just read up on that this weekend). The plane has an impulse coupling, not a shower of sparks. At my request, my local mechanic has talked with Mark Rouch at Top Gun Aviation. Mark is equally stumped about what's going on. Any ideas or suggestions would be appreciated.

I forgot to follow-up on this thread. We ended up overhauling the alternator. The brushes were worn (as someone suggested earlier in the thread). I think I had two problems: a bad voltage regulator and worn brushes on the alternator. Everything has been peachy since I did both those things. Phil

We had something come up today, so we're out (that's 2 less for lunch). Hope you all have fun! Phil

I'll have myself + my wife. Phil

I can make the 2nd or 10th Phil