I just bought a 2001 Johnson 50 having carb problems. Had a small vacuum leak and fixed yesterday. Not sure yet but only way to tell is to try and get the carbs in sync and run semi right. The reason for this post is because I cannot find where the vacuum plug screw would be on the carb. My model #j50vlsib. I have not been able to find much on this motor because the year it was made was the same year OMC went out of businesses(As I was told). I then talked to tech support from BRP. and he talked to a maintenance tech that told him that model # j50plsif was almost identical. The only difference would have been cosmetic. Idk how accurate it is but it's the only lead I have. I started to look at the print on marine engines.com and cannot locate it. If anyone has any input for anything I have said please let me know. This is my first boat and do not know the terminology.