There does seem to be some Hex String labels in there in between raw data blocks. These appear to be buffered by zeros to offset the data blocks to specific offsets. Right after the date there are "4d31", "4d32", etc on consecutive lines. This is "M2", "M3", etc in ASCII. It looks like M2 through M7 repeat every time increment.
Then there are other large data blocks that start with "423a383838383838" after the date sentinel, which is "B:888888" in ASCII. Later in this data block there is a "42726" in the exact same place in each of these large data blocks. This converts to "Bra" in ASCII which I would guess stands for Brammo.
It definitely is an interesting log format, with mixtures of different ASCII, numeric, and date formats all in the same file. A single conversion pass won't decode it. Different hex pairs have to be converted in different ways depending on their position in each line.