lawt:
The data stream always starts with 80, which I can ignore as it's a code to say this is an engine.
You don't say if each of the lines you have printed ends with a specific end marker. If it does you can use that in the second example in Serial Input Basics
If the is NO end marker I suggest you treat the 80 as an end marker and use the same example program. It would mean that you would lose the very first message, but all the others should be received properly.
...R