oisiaa

Exactly, turn key. Modern avionics. Low time engine. Speed mods. When you really look at comps, I think it supports the price nicely. An M20E in similar condition should support this price too. I'm really curiuous what the new MOSAIC rules will do the value of the whole GA fleet. More people competing for the same limited fleet of aircraft will likely inflate prices up the whole chain.

Maybe I'm a sucker, but I paid $155k for a loaded M20C (speed mods, leather, full LED, electric gear/flaps, etc.) with a 120 hour engine/prop. G3X, G5, GTN355/GTX375, GFC 500, etc. I've questioned this pricing since purchase, but going on Trade-A-Plane and looking at J-models in the same price range I continue to be happy with my purchase price. I'm giving up maybe 10 knots on a J (my C will do ~146-148 KTAS), but to get equivalent equipment and engine life you're $200k+ for a J. I believe my plane might be the most expensive M20C ever sold...and I think I'm okay with that based on the market.

My M20C N6821V was personally owned by Ralph Harmon from new in 1971 for about 12 years. He was the chief engineer of Mooney for over a decade including when my (ours/his) plane was built. I didn't know that Mr. Harmon was such a legendary figure who designed the V tail Bonanza.

The whole engine mount was replaced back in 1979 to comply. I personally saw the gussets this past weekend during an oil change. Interestingly, my tail was owned by the Mooney chief engineer at the time (I forget his name without looking in the records) so it received top treatment.

Hmm, the motor mounts were just replaced in the past 2 years (before I owned it). That, coupled with a log entry of a dynamic balance makes me think the previous owner had similar vibration issues.

Page 4-5: Seems to take roughly 10 minutes when below 50F for me. That's considerable ground time, but worthwhile if needed to prevent engine wear.

I found a used 1CH1-6 down limit switch for $75 from BAS vs the near $1,200 that LASAR wants for a new one (plus an 8 week lead time)...I'm going to take my chances for such a price difference.

I'm also operating under the 1970 C Model POH (POH 1203) and have been following 100F as minimum before takeoff based on this same 100-225F range for continuous operation. Seems pretty clear cut for us and can probably inform the discussion for other similar engines (O-360-A1D). 100F takes about 10 minutes on the ground when running 1000-1200 RPM for me with the ambient around 40F.

Will this switch sticking prevent extension? I have a 1971 C model that has an issue with the gear not coming down. The shop cleaned the switch last month, but this morning the gear didn't come down again so I'm looking to have the switch replaced. Just sanity checking that the switch sticking will prevent extension before I spend the money on a new switch. My gear eventually came down after maybe 10 minutes with the gear switch in the down position as I was setting up to manually extend the gear. Edit: Just thinking though this, it makes sense to me that if the switch says that the gear is down, then power to the motor would be removed. I'll check the service manuals when I get home for schematics.

Thanks, I'll try a mag check next flight. It's a two bade prop. I'm typically running 2400 or 2500 rpm which (I'd hope) would be well away from any limits unless the tach is horrendously inaccurate. Already have a smooth landing light lens. The mounts isolators are almost brand new and I'm fairly sure the whole engine mount was replaced back in the 1970s per the logs....even though the last annual did the engine mount inspection AD (past owner). The dynamic rebalance might be the COA even though it was recently done (perhaps improperly).

I just bought a 1971 M20C and it's been great so far across my first 6 hours and I'm still learning the quirks. At cruise speed it seems like there is normally a vibration. I don't think it's a misfiring cylinder since I'm getting good power (~144-146 KTAS). It seems like it might be a propeller harmonic or the prop is out of balance. I've tried adjusting the prop RPM up and down in 10 RPM increments which I'd expect to help if it's a harmonic, but that doesn't really seem to fix it. I also don't notice it 100% of the time so sometimes it runs totally smooth. I tried cracking the throttle until I saw a .1" decrease and then playing with the mixture up/down slightly but that didn't seem to fix it either. That leaves me with the opinion that the prop itself might be slightly out of balance. I'll have to look in the logs, but I'm pretty sure it was just balanced not much more than 100 hours ago. Any thoughts?

Thanks all!

What's the idea with partial carb heat? 148 KTAS is great!

Also, can I trust the % power readout of the G3X? Is that reliable and accurate just based mathematically on MAP and RPM? If that number can be trusted then I can at least know at a glance when I'm below 75% power.

Any recommendations on a comprehensive guide (written or video) on leaning? I recently bought an M20C. I'm an Air Force guy and 99.7% of my hours are in jets or turboprops so the red knob is a bit of a mystery despite reading the POH and other basic guides. It seems almost like an engine self destruct lever if used improperly. The POH essentially says full rich when >75% power unless you have an EGT gauge (I do via G3X), but then doesn't say what to do if you do have an EGT gauge. Ideally, I'd like to be able to fly at WOT at altitudes where >75% power can be achieved without burning crazy amounts of fuel at full rich. The lean assist mode of the G3X requires you to find peak EGT which I understand to be the point where detonation is the most likely so at >75% power I don't really think that can be used safely. My home field is 4,000' so I have questions about leaning for takeoff and climb. Thanks for any pointers to good guides or discussions in this thread!

I got the plane back today. The issue was a sticky downlock switch. Apparently this will cause the gear to not extend if it is stuck in the ground position.

The previous owners were chasing speed. It isn't a huge problem, but a lightweight battery would help with not having to think about CG too much.

My wife is easily motion sick.

Thanks for the tip! I'll consider that when the time comes.

Yes, my battery was moved to the tail. This aircraft has pretty much every speed mod and trick applied to it. There's no free lunch.

I'm running CG numbers right now and even based on 1.5lbs that far back it's going to seriously limit me. My wife likes to ride in the back while we leave the front passenger seat empty. As is, I can do 30lbs in the baggage compartment and 40 lbs in the second rear seat; this puts me right at the aft limit with the gear up. It's no issue if she's in the front seat, but that isn't our preferred setup.

I'm curious about installing a Garmin yaw damper to go with the GFC 500 autopilot. Any idea where the servo is physically installed and what it will do to the CG and how much weight it adds? My M20C is already pretty tail heavy which is great when it's just my wife and me, but it becomes difficult when trying to add adults to the back seat. Moving the CG any farther aft would essentially limit the back seats to children only. Thanks,

Thanks for the information and link to the other post. I'm hopeful that it might just be a microswitch or relay issue. I'll keep this thread updated as another resource for posterity.

After a few touch & gos the gear decided that it wanted to stay up on me. Fortunately the manual extension system did its thing and got the wheels down and locked. I haven't had it looked at yet to see what the cause might be. How often do these types of issues happen and is there a common failure mode? Any leads that I can pass to the A&P would be helpful in getting started in the right direction. I'll keep this thread updated as the inspection and repair goes on.

Thanks, I'll look there, but also open to replies here too.