Browncbr1 Posted March 14, 2021 Report Share Posted March 14, 2021 (edited) 44 minutes ago, David Lloyd said: I knew some people had difficulty with the drive gear from the original mag and not able to set the timing properly. Is that the problem, 20 versus 25 degree timing? But yes, mine is 25 degree. The current surefly mounting flange does not allow it to be twisted enough to get 25° with a certain mag drive gear. You need the mag drive gear that has two woodruff key slots. There is also another single woodruff slot version that works. If you go to aircraft magneto specialist website, he has detailed which gears work. If you don’t have the correct gear, the best you will get there’s about 22° https://www.aircraftmagnetoservice.net/magneto-coupling Edited March 14, 2021 by Browncbr1 Quote Link to comment Share on other sites More sharing options...
hammdo Posted March 14, 2021 Report Share Posted March 14, 2021 I believe SureFly now includes that gear... -Don Quote Link to comment Share on other sites More sharing options...
A64Pilot Posted March 15, 2021 Report Share Posted March 15, 2021 (edited) On 3/13/2021 at 5:48 PM, RobertGary1 said: You may be able to clear this at the runup. If increasing throttle during taxi causes a noticeable increase in rpm you are taxing too rich I don’t understand what your saying, do you mean if you lean? For those that want to lean for taxi, if you lean, lean the snot out of it, lean it as far as it will run decently, you can’t hurt it by excessive leaning at taxi power. ‘The reason to lean the snot out of it is so that when you forget to go back to full rich for takeoff, it will spit and sputter and then you’ll remember. Edited March 15, 2021 by A64Pilot Quote Link to comment Share on other sites More sharing options...
Hank Posted March 15, 2021 Report Share Posted March 15, 2021 30 minutes ago, A64Pilot said: I don’t understand what your saying, do you mean if you lean? For those that want to lean for taxi, if you lean, lean the snot out of it, lean it as far as it will run decently, you can’t hurt it by excessive leaning at taxi power. ‘The reason to lean the snot out of it is so that when you forget to go back to full rich for takeoff, it will spit and sputter and then you’ll remember. I lean mine enough that increasing throttle to taxi uphill requires pushing mixture forward. Keeps my plugs nice and clean! I usually lean prior to exiting the runway. Quote Link to comment Share on other sites More sharing options...
0TreeLemur Posted March 15, 2021 Report Share Posted March 15, 2021 1 hour ago, A64Pilot said: I don’t understand what your saying, do you mean if you lean? For those that want to lean for taxi, if you lean, lean the snot out of it, lean it as far as it will run decently, you can’t hurt it by excessive leaning at taxi power. ‘The reason to lean the snot out of it is so that when you forget to go back to full rich for takeoff, it will spit and sputter and then you’ll remember. Definitely true- I did that a few trips ago. To quote J. Clarkson, some poo came out. 1 Quote Link to comment Share on other sites More sharing options...
the_elkhartian Posted March 15, 2021 Report Share Posted March 15, 2021 Pardon the risk of thread drift... I have the dreaded dual mag. Everybody always makes groaning noises when I say that out loud. I know how it works but why did anyone ever think that’s a good idea? But anyway... Should my single dual-mag ever kick the bucket, can you replace with a non-dual mag setup? Or will I always have a dual mag as long as I have this engine? Quote Link to comment Share on other sites More sharing options...
EricJ Posted March 15, 2021 Report Share Posted March 15, 2021 1 hour ago, wingtipwalker said: Pardon the risk of thread drift... I have the dreaded dual mag. Everybody always makes groaning noises when I say that out loud. I know how it works but why did anyone ever think that’s a good idea? But anyway... Should my single dual-mag ever kick the bucket, can you replace with a non-dual mag setup? Or will I always have a dual mag as long as I have this engine? It's an engine swap to replace the dual mag, but it is possible to do. Several here have done it. The dual mag has some advantages, including better starting spark. As long as it is properly installed it should be fine. If it needs maintenance that your A&P/IA can't do, it can be sent to Kelly Aerospace for inspection or rebuild or replacement. 1 Quote Link to comment Share on other sites More sharing options...
steingar Posted March 15, 2021 Report Share Posted March 15, 2021 Hits have been coming lately. Sent the airplane in for a pitot static, turns out we need a new altimeter. Go to fly it after that and it won't start. Needs a new starter. My wonderful Mooney is turning into a maintenance hog this year. Quote Link to comment Share on other sites More sharing options...
Will.iam Posted March 15, 2021 Report Share Posted March 15, 2021 On 3/13/2021 at 3:06 PM, David Lloyd said: Was going to take a short trip at lunchtime today, start was normal as warmup, taxi, going thru the checklist. Runup was routine, mag drop was about 75 each, as was carb heat, prop cycle, etc. Tower clearance, turning onto the runway, it felt like a flat tire, or rumble strips on the highway. I let it roll on the runway a little, fed a little power, the engine shook, ran rough, backfired a couple times. Pulled power, told tower there was a problem and was going back to parking. Stopped along the way, ran it up a little, yes it was plenty rough. right mag was smooth, left mag wouldn't run. It would cause a backfire about once a second or so, but otherwise the left mag wasn't going to run the engine. It was working great until it wasn't. I'm expecting to find some nylon gear teeth sheared inside the mag. I was planning an annual at AGL end of the month, was going to ask Lynn a few questions about the SureFly SIM. I guess this hastens that conversation. In the meanwhile, I need to get the plane up there. Anyone have a spare, useable, shower of sparks Bendix mag they could loan/rent me for 6 weeks? Over the years I can only think of a few aborted trips due to problems found on the ground. Two vacuum pumps dead on startup. One, maybe two alternator/regulator/wiring not supplying power on startup. A flat main strut on the Bonanza. After having a SB done on the Bonanza interior door handle, I found myself locked in the airplane after taxi to the fuel pump (mechanic got a 5 AM wakeup call). That's it, all remembered. Not bad for 43 years flying nearly every week. A whole bunch of stuff broke while flying, a few more things were found after a trip like a big puddle of oil in front of the hangar, coming out of my engine right then. What mechanical surprise has stopped your trip before getting started? Might check for a broken ceramic insulator on sparkplug by swaping top to bottom on suspected cyl and see if the problem goes to the other mag. I had brand new tempest fine wire plugs installed and one cracked the insulator with less than 24 hours of operating time on it. Quote Link to comment Share on other sites More sharing options...
A64Pilot Posted March 15, 2021 Report Share Posted March 15, 2021 (edited) There really is nothing wrong with a dual mag. It’s just as reliable as independents, there is nothing in your accessory gearbox that can break and one mag still continue to function, the only real single point of failure for a dual mag is the single drive shaft, and has anyone every heard of one of those breaking on a mag? The only real issue is parts availability, I believe the dual mags are no longer manufactured? However there is no logical argument for a points based magneto, none. Lawnmowers went to electronic magnetos decades ago as did everything else, outboards etc. You can easily have self generating electronic ignition, back to lawnmowers, weed eaters etc, and there is no reason not to have an electronic module to replace the points etc in a standard magneto, just there isn’t enough money in it due to Certification hurdles and low volume. Edited March 15, 2021 by A64Pilot 1 Quote Link to comment Share on other sites More sharing options...
A64Pilot Posted March 15, 2021 Report Share Posted March 15, 2021 (edited) I believe the only really logical case to go to independent mags could be made at overhaul. Lycoming I believe will swap out your case for one with independent magnetos if you buy a zero timed engine, they may even discount it. Edited March 15, 2021 by A64Pilot Quote Link to comment Share on other sites More sharing options...
RobertGary1 Posted March 15, 2021 Report Share Posted March 15, 2021 13 hours ago, A64Pilot said: I don’t understand what your saying, do you mean if you lean? For those that want to lean for taxi, if you lean, lean the snot out of it, lean it as far as it will run decently, you can’t hurt it by excessive leaning at taxi power. ‘The reason to lean the snot out of it is so that when you forget to go back to full rich for takeoff, it will spit and sputter and then you’ll remember. The test to determine if you’ve leaned enough is to give the plane full throttle. If there is more than a few hundred rpm increase it’s too rich. Quote Link to comment Share on other sites More sharing options...
A64Pilot Posted March 15, 2021 Report Share Posted March 15, 2021 10 minutes ago, RobertGary1 said: The test to determine if you’ve leaned enough is to give the plane full throttle. If there is more than a few hundred rpm increase it’s too rich. Still don’t understand, if you lean an engine excessively al low power, if you advance to full throttle it will quit. I can’t imagine being able to lean so much that an engine will idle at full throttle? Only thing that does that is a Diesel. Quote Link to comment Share on other sites More sharing options...
David Lloyd Posted March 15, 2021 Author Report Share Posted March 15, 2021 28 minutes ago, Will.iam said: Might check for a broken ceramic insulator on sparkplug by swaping top to bottom on suspected cyl and see if the problem goes to the other mag. I had brand new tempest fine wire plugs installed and one cracked the insulator with less than 24 hours of operating time on it. Four plugs fired by the left mag would have had to suddenly fail as I was taking the runway. Nope, mag sudden death. Quote Link to comment Share on other sites More sharing options...
RobertGary1 Posted March 15, 2021 Report Share Posted March 15, 2021 24 minutes ago, A64Pilot said: Still don’t understand, if you lean an engine excessively al low power, if you advance to full throttle it will quit. I can’t imagine being able to lean so much that an engine will idle at full throttle? Only thing that does that is a Diesel. Properly leaned on the ground it kind of stumbles and then just doesn’t increase rpm when the throttle is advanced. You can move the throttle back and forth from 1/2 to full and there is no reaction from the engine. It’s how I test I’m leaned enough. Quote Link to comment Share on other sites More sharing options...
EricJ Posted March 15, 2021 Report Share Posted March 15, 2021 2 hours ago, A64Pilot said: The only real issue is parts availability, I believe the dual mags are no longer manufactured? You can buy new ones from Kelly Aerospace. They claim their cases are superior to the Bendix. Quote Link to comment Share on other sites More sharing options...
David Lloyd Posted March 21, 2021 Author Report Share Posted March 21, 2021 Just a follow up. Pulled the left mag yesterday. A couple teeth missing on the nylon gear. Apparently it continued to spin and provide a spark, but not at the proper time. Engine would backfire every couple seconds when the ignition switch was on both. Hammdo came to the rescue with a serviceable magneto. Just send it back when you're thru with it. Terrific guy, but I think everyone already knew that. Airplane is going to AGL in Morganton in another week. Plan is to install a Surefly SIM on the left side. 4 Quote Link to comment Share on other sites More sharing options...
carusoam Posted March 21, 2021 Report Share Posted March 21, 2021 Great follow-up David! Awesome pirep for @hammdo as well... Got any pics of the cog with missing fangs? Best regards, -a- Quote Link to comment Share on other sites More sharing options...
hammdo Posted March 21, 2021 Report Share Posted March 21, 2021 Thanks for the kind words David! Always happy to help out... -Don Quote Link to comment Share on other sites More sharing options...
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