Levels issue with acoustic guitar pickup

Is there a pre amp in the signal path? 
Piezo pick ups need to be driven by a pre amp otherwise they are very low output and thin sounding. 

If this is not the case then have you tried using another source into the same input. 
What happens with a mike? 
If the Motu has a software mixer then check that too. 


Normally if you set the gain properly at the interface then that is reflected by the tracks level meter. 
Which is another question. Is the track meter showing a good level?  
If so then what is happening is your track view settings are zoomed in to far. 

This pickup is a magnetic device not a piezo device. It can be run in either active or passive mode. In active mode it has a built in preamp and needs a battery and requires no preamp at all.  It outputs a higher level in this mode.

Have you put the battery in and used it in active mode. I would try that before doing anything else. 

Passive mode is for when your battery goes flat (and it will!) on a gig. In this mode I would imagine a preamp might be helpful as it will put out a lower level of signal and might need some impedance matching.  

No dudes! Forget all that about preamps and batteries, all that is rocking and I'm not short of level -  except when recording. 

That's the strange part, the MOTU meter is through the roof without any help from the input gain and I'm dying in the headphones - but the record level is low.

The M80 has a battery for Active mode but functions perfectly well without it in Passive mode. BTW: It's a beautiful pickup! Not cheap but you WILL sound great! I'm very happy with it.

I had a Fishman before, which needed a little square battery inside the guitar, what a drag and it sounded like a fake acoustic patch in an amp sim. The Baggs really sounds like an acoustic guitar even when you're not using a mic.

Glad you figured it out. Kinda thought this was the case when you said your Motu meter was rockin'. 

The mike was probably was running your monitors back into the motu. 
I've done that before too as I use a mixer for input and have to remember to mute all the unwanted channels when swapping around.