2000 Johnson 150 - Only 1800 RPM Under Load

[Jose67]

That is what it sounds like. When I reached that RPM range it is like some circuit is cutting spark to the cylinders. I have tried disconnecting (one at a time) port side temp sensor, starboard temp sensor and shift switch all with the same result, can not get over 1,800 rpm. Does the shift switch activate when the button is pushed in or when the button is out? Looking at the shift linkage where the switch is mounted in it looks slightly curved and not straight. Maybe causing it to activate when it is not supposed to? I am going to try hooking up a spark tester or timing light and check each cylinder for spark at the RPM range that I start to experience the problem.

 

[Jose67]

Well after checking just about everything in the electrical system (at least twice) and not finding anything wrong other than a bad shift switch (at least not a complete waste of time) and doing a link and sync I figured it was time to move to the fuel system.I started by removing the starboard carbs removed the bowls and what do I see.... NO HIGH SPEED ORIFICE INSTALLED IN THE BOWLS!!! I am sure I have found my problem. I will have to order 6 of them or maybe I should contact the PO and see if he has them laying around somewhere. Does a #73D orifice should right for this engine? I guess anything would be better than an open hole in the high speed circuit,lol. I will update in a few days when I receive the orifices and get them installed.

 

[Jose67]

UPDATE. Received 6 new #59D jets, installed them in the high speed orifice holes took boat down to the creek and lo and behold the engine will now rev over 1,800 rpm with ease. As it turned out I was barking up the wrong tree for two weeks but finding a bad shift switch first had me convinced it was still an electrical issue. I really appreciate everyone's comments and input on this issue.