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Little help. Just got the aircraft and going through my punch list after some research. FP/MP combo gauge. Fuel pressure needle is upside down and mirrored on wrong side of gauge. Fuel pressure indication is correct, but mirrored across gauge. Need to clean gauge fitting? Flip the needle how? Failing gauge? Just replace it? Attached a quick vid and thanks for any help. FullSizeRender.mov

Anybody have a POH handy that shows upper and lower fuel pressure limits for a 77 M20J?

Anyone been successful at finding a way to replace the fuel pressure gauge and getting that fuel line out of the cockpit?

Hello to all..two weeks into aircraft ownership with 1964 M20C. Already on the board with my first question / problem. Fuel pressure is on the high side of green arc 6.5 - 7. Any thoughts on where I should begin with high fuel pressure? Previous topics w high pressure seem to be in the injected engines or did I miss HFP post in carb engines? Thanks, G

HI All, I just had a complete overhaul and new fuel pump installed as well and have about 28 hours on the engine so far. The issues (or maybe not an issue) is that the fuel pressure runs about 30 psi ( I was told this will come down once the fuel pump wears in), but it will run constantly about 29-30 psi, then after a few minutes drop to about 25 psi for only a few seconds. I've confirmed the readings on both my EI fuel pressure gauge as well as the original fuel pressure steam gauge. Any ideas? Thanks! Jim

Hi Mooney Drivers, I have a 77 201 with firewall forward with 30 hours. At higher altitudes I'm seeing my fuel pressure on stock gauge oscillate from 25-21 and fuel flow jump from 10.3 to 9.7-ish. All is good on climb and solid on descent. Altitude wise I'm talking 10-11k. Soon as you hit the boost goes right to 26. Thoughts?

I have a 1979 M20k with intercooler and Merlyn Wategate. I recently had the fuel pump and mixture controller replaced/overhauled. I've had 2 shops, including a Mooney service center, attempt to set up the fuel system. I get full rich at idle, 24gph full rich at full power, but as I reduce manifold pressure my TIT/EGTs rise. I usually get about 18gph at 2600/30in TIT 1350 in climb and now get about 15-16gph with TIT approaching 1500. In cruise I have to use full mixture to get 75 ROP and at low altitudes it is more like 50 ROP. This M20K has always been set rich - firewall mixture was over rich on take-off (more than 24gph) and I had to set fuel flow in run-up so I would be at about 24gph on take-off roll. The current shops are setting to the book. Initially one would say it is one of the replaced components, but I'm thinking this may be an issue that had previously been compensated for by this over rich setting. Has anyone seen this type on non-linearity in the fuel system such that you get full rich at idle and take-off but run best power or less flows in between (all cases firewall mixture)? One of the mechanics suggested that the Merlyn may be driving a higher MP than the mechanical fuel control is "expecting" below full power. Any thoughts?

So I've been flying my plane for a couple of months now and am starting to get used to it. But as I am getting more familiar with it I'm starting to notice a few things that I didn't before I bought it. When starting, typically when I engage the starter it doesn't kick the bendix out on the first try but it always always does the second time. I am planning on getting some silicone spray lubricant and squirting it in and am hoping that will work for a while. Second is that I have an ADF but it doesn't work; I was thinking of just taking the antenna off. I can easily just un-hook the wire from both the top of the cabin and the top of the vertical stabilizer. As long as the ADF is marked INOP is there any problem with this that anyone can think of? I'm considering having the unit removed at my next annual anyway just to get rid of the weight and save complexity (more powered stuff in the cabin is more chance for a short). But I figure if I pull the antenna with its rubber bungee hanging out in the wind I can only be helping my airspeed. Third is that on the Arrow I used to fly I could see changes in fuel pressure on the fuel pressure gauge when I adjusted the mixture. The gauge was marked in PSI and in GPH. On my Mooney changing the mixture doesn't seem to change the measured pressure at all. Without the boost pump the pressure is always at the VERY low end of the green arc, but with it (a new Whelen replacement) it's about 1/3 of the way up, no matter what I have the mixture set to. Is this actually normal? I set mixture by the EGT so I don't need it, but this is not what I was expecting. The last is that the aircraft always wants to bank left. It's barely noticeable when in normal cruise flight, but it becomes pronounced when the flaps are extended. With full flaps it will bank at perhaps 5-10 degrees per second if I don't hold it level even though the ball is centered. Am I looking at an expensive adjustment to get this fixed or should this be fairly inexpensive? Inexpensive in Mooney terms, of course. One 'bonus' topic is that I've got a David Clark H10-13X that uses an external battery box but can be cabled directly if the appropriate plug is installed. This would be in addition to the regular audio jacks. Has anyone had this done? It looks REALLY simple if I can find the right cable and I'd love to get rid of the battery box and it's tangle of extra cables. I can't seem to find the right cable from Aircraft Spruce or on the (mostly useless) David Clark web page. Thanks for all your help!

I have an 1986 M20K 252 and pretty proud of it. But I do have a problem with the engine that I can by now almost predict on hot days. After the plane has sat all day in the sun it will start up very nicely but when applying take-off power the engine will quit. If I put on the low boost pump it will not quit and continue running. Mostly in the flight levels above 100 and some cooling it will operate with the low boost pump off but I have had one flight lately where it would start to run rough and stop if not re-engaging the low boost pump (maybe not enough cooling time). Next morning and with cooler temperatures normal operation. This happens with outside temperatures above 90°F (33°C). This is clearly temperature related. First I suspected vapor lock but now I am not so sure about this since vapor locking should terminate once it has been pushed out of the system once. The fuel pump has recently been revised but I still suspect some problem with fuel pressure or maybe an air leak somewhere in the system (there is no fuel leak noticeable though). The maintenance shop believes it might have something to do with the fuel selector valve. Any ideas on how to proceed with troubleshooting?