Go to Miramar, that's not a problem in any season. Talk to the locals and hire a lancha which will take you to Carti and load the bikes directly onto the boat where it is moored. KLR no problem.
Someone here recently did the boat trip from Miramar to Carti very cheaply on a small cargo boat. It took something like 6 hours.
Voyage on the Stahlratte is well worth the adventure getting to it. Go for it!
How much does a man live, after all?
Does he live a thousand days, or one only?
For a week, or several centuries?
How long does a man spend dying?
What does it mean to say “forever”? - Pablo Neruda