These are special instructions for fitting the large Garmin 50/200kHz transducer (part number 010-10272-00) supplied with the Garmin 400C and some other Garmin sounders. This transducer will fit the Profish 400 Lite transducer socket but won't fit the Profish 440.
The 400C transducer is reasonably big making it a firm fit in the socket of the Profish 400 Lite. The key point is the transducer may look as though it's too wide for the socket by roughly 2-3mm, but with a little gentle pressure will seat in place. The rest of the installation is similar to that given under the “How to install a fish finder” topic.
This Garmin transducer is the large one with part number 010-10272-00. You can find this part number printed above the barcode on the header card the transducer comes packaged with. Garmin part number 010-10249-00 is the smaller transducer seen in the “How to install a fish finder” instructions and easily fits the Profish 400 Lite.
The transducer looks as if it’s too wide for the socket in the keel of the Profish 400, but does press-fit into place with a little gentle persuasion. Here's what it looks like before the process:
The thin square shaped splash skirt at the front top of the transducer needs to be removed so it fits forward into the front of the socket in the Profish 400 Lite. I clip it off with cutters then tidy up with a file or sanding disc.
Once the skirt has been removed fit the transducer mount bracket (part of Viking’s universal transducer mount kit) and the transducer is ready to be pressed into the socket.
The final step is to press the transducer in place. This takes a small amount of force but is easily done. The mounted transducer only protrudes a little from the socket and is protected by the full length keel strip on the Profish 400 Lite. The rest of the installation instructions can be seen in the "How to install a Fish Finder" topic.