First off , hello everyone! I have a sportster which was running fine last season just before the end of the season the throttle cable broke , which I fixed , winterized it and put it away for the remainder of the year . This season I took the boat out on the water , the drivers side engine will not exceed 4000 rpms . I took the boat out and ran it in my driveway in neutral it will rev to 4000 which I believe is normal, in gear it will reach to 7000rpms what can cause the low rpms when it’s in load ? . I have since cleaned he carbs , swopped rectifiers from one side to the other , checked compression I’m getting 150/145 on the problematic engine , the other is reading slightly higher. Not sure what else to check or replace . Please keep in mind I am a novice when it comes to these engines or boats in general. Any help would be greatly appreciated