Had the same exact experience, bunch of zip ties. Got the "Snap Clamps" from the local BRP/OMC Dealer.
I ended up using mostly size 6, except where the hose attached the fuel/oil pump, and needed a size 8 for that.
For the record, my 1989 Johnson Service manual has 3 photos: Tie wraps and the metal worm screw type, these both have an "X" through them. They basically say you are supposed to use the Snap Clamps, at least on the oil lines. I used them for both the fuel and oil lines, which will make changing the fuel filter easier, etc.
The Oetiker clamps look pretty good, but I think once crimped, you need to destroy them to get them off. Also, it is pretty tight in the engine compartment on mine, so I opted for the Snap Clamps which are reusable. The Oetikers look like a good choice for the external fuel line/bulb, if you have an external tank where you could easily redo them if needed.
Forgot to mention they were about $1 each.