Cutting and fitting coolant hoses, oil hoses, fuel lines and running the Rotax wiring. I decided to upgrade the oil hoses with MIL 6000 hose. It has a 10 year life and it a bit more robust. Cutting and fitting is actually easier than with the hose supplied by TAF. The problem is the AN8 fitting with a 12mm ID hose.... difficult to fit is an understatement. I will go with with metal fuel lines as much as possible in the engine compartment. My son (also a pilot) was visiting so, of course, I had to put him to work!