Re: limp mode
I just had similar problem with my Yamaha 9.9 T9.9 ELRT. Had just rebuilt carburetor and fuel pump. It started easily but wouldn't generate much power. I had seen some deposits on the 48 jet shaft in the groove between the screw threads and the slotted head, and thought maybe they were residue of a gasket, but called Yamaha Customer Service and was told to clean the slot, which I did with a spray carb cleaner and an old tooth brush. I also used broom straws to 'rod out' the various openings in the carb, and didn't really find anything. Then focused on possible areas that could lose vacuum. I torqued the spark plugs per specs. Also found loose press-fit angle fitting where gas enters carb and used threadlocker on that. Engine now starts and runs great. I don't know which thing fixed the problem.