Adding RPM to EDM 730

[Nukemzzz]

So 34X is getting very close to airborn again. During the run up my IA noted the tach is jumpy. Before it was grounded in March for the cracked engine case I noted it was a little jumpy but apparently it’s worse now after relocating the Tach location which made the cable a little too long and it zigs and zags more. So now I’m thinking on what to do about this gremlin...

Things I’m considering:

1. Install an EI TSO tach. The flight time function sounds useful. I just don’t like that it’s not 3 1/8” and I’d need to put an adapter in my brand new panel and getting one set up for this plane would take some lead time apparently. 
2.  Send the gage off for rebuild and get a shorter cable. Anyone recommend a shop?  It would be nice to keep the stock steam gage.  I like the vintage style and feel of flying the classic. 
3.  Add RPM to my EDM 730.  This is legal I’d assume until the primary tach doesn’t read zero RPM when the engine is shut down(kidding not kidding...lol)?  What I don’t know here is if I have to send it back to JPI to enable this or do I just get the bendix style sensor and add the pins to the plug?  How about if I add MP and OAT...do I have to send it back for that?

Side note...in this plane you have to remove the vacuum pump to get the tach cable off the engine.  Bad luck on that.

Last question. I have a newer prop that doesn’t have AD’s.  I assume this doesn’t change the red zone on the tach right?  I still need that mid RPM red zone if I order a tach right?  

Thanks

[Nukemzzz]

66’ E. Red at 2100-2350.  I know there are some arguments about if this should be yellow.  Not sure if we have sorted when it is no longer needed. 

[jaylw314]

The 730 RPM option is detected automatically by the instrument, it doesn't need to go back to JPI.  It'll get read as just another parameter like fuel flow or oil temp and be put in the scanning cycle that you can step through.  Alternatively, you can change the instrument to an 830 in the setup menu, and I think it will display RPM as a big semi-circular display at the top.  I'm not 100% sure if it will do that without the MAP hookup as well, but I'm guessing it would still work.

Obviously, if your IA is unwilling to sign off on your primary gauge, this doesn't help since you still need it.

IIRC, in the STC for my Hartzell prop/engine combo, it specifies the RPM gauge should be re-marked to remove the cautionary zones (which is not relevant since I have a digital EI gauge).  I'm not sure about your combo, though.

[Nukemzzz]

6 hours ago, jaylw314 said:

The 730 RPM option is detected automatically by the instrument, it doesn't need to go back to JPI.  It'll get read as just another parameter like fuel flow or oil temp and be put in the scanning cycle that you can step through.  Alternatively, you can change the instrument to an 830 in the setup menu, and I think it will display RPM as a big semi-circular display at the top.  I'm not 100% sure if it will do that without the MAP hookup as well, but I'm guessing it would still work.

Obviously, if your IA is unwilling to sign off on your primary gauge, this doesn't help since you still need it.

IIRC, in the STC for my Hartzell prop/engine combo, it specifies the RPM gauge should be re-marked to remove the cautionary zones (which is not relevant since I have a digital EI gauge).  I'm not sure about your combo, though.

I can change it to an 830?  Learn something every day!

[1001001]

23 minutes ago, Nukemzzz said:

I can change it to an 830?  Learn something every day!

Yeah, it's easy to do, check the installation manual, available on JPI's web site.  I added RPM, Manifold pressure, and OAT to my 730 at the last annual and all we had to do was change the instrument type to 830 and reconfigure the display a bit. 

[carusoam]

What problem you are having...

1) Primary instrument isn’t working...

2) Not fixing that and using an 830 instead...

Stay focussed...

Sounds better than it is...

But, if you want to spend the dough... go JPI 900 for a primary instrument.

Otherwise the EI tach is a low cost and primary instrument...

Best regards,

-a-

[StevenL757]

For @Nukemzzz, why wouldn’t you want to jump to an EDM900 as a certified instrument and free up that space?

[Nukemzzz]

3 hours ago, StevenL757 said:

For @Nukemzzz, why wouldn’t you want to jump to an EDM900 as a certified instrument and free up that space?

I just redid the panel, haven’t even flown it since I did. Burned a whole lot of cash already when the engine case cracked in March and I redid the interior carpeting and walls. Overhauled the nose gear. Installed a transponder. Have yet to fly it since the case crack and it’s already up for annual, in process as we button up the engine. I bought the plane in December...flown it 15hrs. Insurance is about due again and I’m not hearing anything from them which concerns me. Also, I’m still trying to get my medical and don’t have my PPL yet...LMAO. I think I’m crazy. 

[Nukemzzz]

3 hours ago, carusoam said:

What problem you are having...

1) Primary instrument isn’t working...

2) Not fixing that and using an 830 instead...

Stay focussed...

Sounds better than it is...

But, if you want to spend the dough... go JPI 900 for a primary instrument.

Otherwise the EI tach is a low cost and primary instrument...

Best regards,

-a-

Primary still works, it’s just jumpy. But as I pressed send on my original post I did think “isn’t it about to fail and then I won’t have a primary?”. So yeah, I need to address that. 
 

We will start it again this week.  Let me see if straightening the cable addressed it first. My preference is to rebuild the stock I think. But where to send it?

 

[carusoam]

If sticking with the original...

I used an instrument shop I found in Trade-a-plane...

I sent it there when the needle fell off because it bounced so much it finally hit the peg...

Turns out, it needed a new cable, they put the needle back on and sent it home... wish I could remember who they were... 

Technically what mine really needed... proper yellow zone and red line painted on it... mine has a decal stuck on its lens still... (on the shelf art)  a real instrument shop is capable of re-screening the art... it will look brand new when done... for little dough...

It also would have benefited from the proper length of cable... apparently a Mooney specific length...

Call your MSC... check on the price for a new cable... it can’t be horrible.

We can always send the factory a message of what the price you are willing to pay is...  some things got lost in translation over the years...  

Near off the shelf, manufactured by somebody else... doesn’t get the same margin as parts built in house to Mooney specific drawings...

One end fits Lycoming parts... the other fits the instrument parts... the only thing Mooney is the length... (which is in between) 

Best regards,

-a-

[jaylw314]

19 hours ago, 1001001 said:

Yeah, it's easy to do, check the installation manual, available on JPI's web site.  I added RPM, Manifold pressure, and OAT to my 730 at the last annual and all we had to do was change the instrument type to 830 and reconfigure the display a bit. 

It's actually not documented in the installation manual, but it's in the main setup menu.  I think the item is "Instrument Type" and it should say "EDM-730" now.  I initially thought it was just an information field, but all you have to do is press "Change" and it turns into an 830.  Thanks to whoever on MS pointed that out, there was an old thread about it.

[1001001]

3 hours ago, jaylw314 said:

It's actually not documented in the installation manual, but it's in the main setup menu.  I think the item is "Instrument Type" and it should say "EDM-730" now.  I initially thought it was just an information field, but all you have to do is press "Change" and it turns into an 830.  Thanks to whoever on MS pointed that out, there was an old thread about it.

I could have sworn I saw it in either the installation manual or the pilot's guide, but I've just been through both of those documents, and I can't find it.  I guess I found it by playing around with the configuration menus.

[jaylw314]

Either that or you found the same thread I did here on MS