Re: 40 hp johnson wont go over 4200 rpms
You definately need to look at the carbs when they are completely installed, not when you have then off. Link and Sync can definately rob you of that many RPMs if everything else is operating properly. And the carbs have to be on the motor for an L&L to be effective. For me, I usually make sure the butterflys are completely closed when the motor's control is in idle (not to be confused with the start lever in start position. If you have done your L&L correctly, this will take care of itself, so just leave the start lever alone until you test the whole thing at the end) There are some small cutouts at the top of the butterflys that allow enough gas to get through to idle. So after making sure that the butteryflys close, then check to make sure (as Ed suggested) that the butterflys are wide open (that is, they are completely perpendicular to the carb thoat itself) when the control is in WOT position. Looking in the carb throat when the butterflys are in this position, you should only be able to see the side of the butterflys. Once you have these two positions correct, most everything else is based on RPMs--at certain range of RPMs at idle, and a certain range at WOT. Only a manual (or one of the fellows on here who are much smarter than I am, which is probably most of them can tell you your ranges. <br /><br />You know, it's kind of funny, but I struggled with this problem for a few seasons before figuring it out. I was always getting the manual's listed settings very close, but there always seemed to be one variable that I could only get sort of close (like the difference between START and IDLE) but not perfect, so I just usually guessed at it. But NOW I understand that every single one of the variables have to set correctly for you to get anything even close to an engine's peak performance. And they all have to be set while the engine is completely assembled and functioning.<br /><br />Anyway,good luck. Carb problems seems to be one of the most posted items in any of iboats' forums. But there are tremendously talented people who visit these pages, and, for me, I often thank God I found help like this. <br /><br />Good luck
