THis subject has been covered before by others. This issue has been observed on my R-25 as well.
It's an issue where engine bay fumes or engine exhaust residues or whatever get drawn into the bilge area and then push/sucked out through seams and openings in the panels behind the 'head' end of the forward berth. These are panels that are on the starboard side the speaker is attached to same panel on the port side.
I removed these two panels today and will be taking them to the Ranger Kent factory on Friday to have them re-covered with a vynal material rather than the white monkey fur material.
While I had the panels off I examined them and found some poor assembly techniques that contribute to the black streaking. First, the panels are made with two pieces of plastic marine starboard. When they are joined or butt up to each other they are sealed with a vynal strip. This strip is glued to the starboard. Unfortunately the glue does not do a good job as I found the vynal strip were practically falling off. Also, when the panels were being screwed to the backing material the assembler wasn't sure exactly where to place the screws and made several attempts. This resulted in multiple holes being drilled through the starboard. These open holes allow the black media from the engine bay to penetrate the starboard and into and onto the white monkey fur.
I show a number of photos below that hopefully clarifies some of what I've posted above. I also show photos of what you see behind the panels when they are removed.
It's an issue where engine bay fumes or engine exhaust residues or whatever get drawn into the bilge area and then push/sucked out through seams and openings in the panels behind the 'head' end of the forward berth. These are panels that are on the starboard side the speaker is attached to same panel on the port side.
I removed these two panels today and will be taking them to the Ranger Kent factory on Friday to have them re-covered with a vynal material rather than the white monkey fur material.
While I had the panels off I examined them and found some poor assembly techniques that contribute to the black streaking. First, the panels are made with two pieces of plastic marine starboard. When they are joined or butt up to each other they are sealed with a vynal strip. This strip is glued to the starboard. Unfortunately the glue does not do a good job as I found the vynal strip were practically falling off. Also, when the panels were being screwed to the backing material the assembler wasn't sure exactly where to place the screws and made several attempts. This resulted in multiple holes being drilled through the starboard. These open holes allow the black media from the engine bay to penetrate the starboard and into and onto the white monkey fur.
I show a number of photos below that hopefully clarifies some of what I've posted above. I also show photos of what you see behind the panels when they are removed.