Had a problem with my iWAY 350C shutting off after about a half hour of operation in hot weather. Unit is mounted on a RAM handlebar mount. Others here noted the same problem. Some linked it to heat, others to vibration.
I contacted Lowrance and sent them copies of the messages on this board showing others had had similar problems. Got a return authorization even though my unit had been out of warranty a few months. They received it and sent a note back saying they'd send it to engineering for test and evaluation. I responded thanking them for their offer but asked them to send it back "as is" and I would limit its use to my truck and get a specific unit for motorcycles (the iWAY is not weather proof).
The next thing in this sequence is a new 350C was delivered by UPS--no charge. Of course, I can't verify the malady is fixed until hot weather arrives, but just wanted to post this note to let everyone know what a great customer service operation Lowrance is.
If you're having problems with their products, I highly recommend you contact them. Nothing to lose except a few minutes at the keyboard or on the phone.