If you´re looking to ride through La Mosquitia in Honduras, here´s some info to help you with your decision. Back in September I road with another guy (Omer from Israel) into La Mosquitia, and we found out at the first lagoon that we were going to have to transfer our bikes from big canoe, to big canoe, 5 times before we reached a rideable route. (at least that´s what they told us in the small town across the lagoon from Palacios) That included taking one of the canoes out into the ocean. No one there, including ourselves, had ever loaded a motorcycle onto a big canoe, so we decided it wasn´t worth the risk of losing the bikes. You may feel differently when you get there though. That same town was also the one and only place on my trip that felt like I had stumbled upon something I shouldn´t have. Aside from people shooting guns in our immediate vicinity, there was just an overall bad vibe. On a high note, one of the best nights of my trip was spent with a family in a beachside village on the ride back to Trujillo.
On your map, when the road east of Trujillo nears the beach and then runs parallel to it, the road is the beach, with plenty of soft deep sand. It´s about 15 miles from there to the first laguna and the town mentioned above, where you have to take a boat.
I know you have a waterpurifier so you´ll be good there, and if you plan on pushing all the way through, an extra gallon of gas for your KLR may be worth it: we didn´t get far enough to find out. You´ll only have to carry it for the first 50 miles anyways.
Finally, be careful crossing the rivers flowing into the ocean. It's much different than crossing a river with a rocky bottom. Your bike sinks like it's in quicksand, and depending on rain, the water can come up over your seat. Our bikes would have unquestionably been lost if there weren´t two of us there. The only way we could move them in the water and sand was by standing in front of the bike facing the headlight. Grab the front wheel and roll the wheel towards you, essentially making the bike a front wheel drive vehicle.
Sorry for the huge post, but I thought the random info may be helpful. In case you were looking for an opinion, IMHO I'd pass on La Mosquitia unless you're with someone else. That may be a biased opinion because I hate riding in deep sand, but Omer, who´s a much better rider than I, were both in agreement that we would have been screwed riding there solo. You can always leave your panniers in Trujillo, explore the beach, and return to Trujillo the following day.
Hope this helps!