DrQuinn

Problem solved thanks to this and it was an easy fit. Thanks again for pointing me in that direction!

Thank you for your enlightening explanation.

That sounds like a great place to start, thanks.

I recently had a new GI 275 configured as an engine instrument. When it was first installed the manifold pressure rapidly fluctuated +/- 2.5 so much so that you had no idea what it was reading. The old gage was rock solid but I was beginning to strongly suspect that it was reading low. I'm speaking a little beyond my technical knowledge but as my mechanic added something onto the line to limit the size of the pressure line which helped bring it down to +/- 1. Later I think he said he pinched a bit of the line a small amount with a pair of pliers which helped a little more however, still, once I apply any decent amount of power it fluctuates about +/- .7. Can anyone explain in layman's terms what we need to do to get it down to a usable level?

I suppose I could consult the parts manual but to save time can anyone tell me if there is supposed to be a sleeve over the track of the baggage door? When I got my plane back from annual the baggage door will not stay open because the inside metal arm with the tab on it doesn't stay within the track. FYI - the weight of the door closing from full and contacting your head really hurts.

The Brittain PC in my M20C went a couple years ago and although it might be serviceable I am considering upgrading to something a little bit more elaborate that will hold an altitude and course. Searching here I've seen the odd post about a couple companies getting close to providing something but, perhaps in laziness, I am looking for a list of my options including all of the equipment one would need.

I recently did the same thing with the same model cap. I found a used replacement on the internet by looking for the part number. Luckily a couple of different aircraft use the same part. I have one spare now.

Thanks for all the responses. To confuse matters I checked it with engine off and it actually under-reads what the pressure was by 1 1/2". My mechanic suggested that he could have it calibrated or that I just play around with different settings over the summer (while keeping an eye glued to the cht's) and keep records so I can find settings my airplane like.

Thanks for the hint, I will definitely check on that at startup next time.

I use an external gauge to set RPM and I have no reason to believe that it is inaccurate; it gets the same readings as my mechanics. I will have to check the manifold pressure reading with engine off next time I'm at the plane. I have a EI ubg-16 but it's not hooked up for fuel flow or MP unfortunately.

I started to keep some more detailed stats to see how not even close to the book numbers I am getting. Depending on altitude I typically setup for closest settings under 75%bhp and lean. Usually I am 15 or more mph short of the known unrealistic POH figures. I just started keeping fuel statistics though and I am running at 7-8 gph, certainly way better than the books range of 9 - 9.4. I have a portable tach that gets the actual RPM, leaving either I'm leaning waaaaay too much (which I don't think I am) or the MP gauge is off by an 1 - 1 1/2 ". Does anyone know if this is likely? Would my mechanic be able to verify the meter similar to the tach?

Merci / Thank you Yves. Looks like Ill be back in business quick.

Lol thanks I am a bit of a gambler but "$100 untested and uninspected" a win wouldn't feel like much of a win and as for a loss ....

Thanks. Before I posted I searched solenoid and came up with some information which wasn't specific enough for my lack of experience. A discussion that resolved to "Skytec metal can ones" and https://www.mcmaster.com/#solenoids/=16scf3q.

My M20C has decided she loves me so much she doesn't want me to leave her alone so she leaves her electrics on after I shut off the master to keep me around. With a little help from my mechanic I suspect it's the solenoid. The parts manual lists the solenoid as part number 001464 which I cant seem to source from anywhere. Does anyone have the part number of a suitable replacement? Thanks! Dave.