1997 115HP Yamaha Bogging Down

[SouthCarolina1]

I have a 1997 115HP Yamaha S115TL. It has ran like a top for awhile but now it is giving me grief. After driving the boat for awhile anchored down, and then going to take off and the motor would be a little bogged down. Slow acceleration but would plain out and would not go above 4000 rpm. This happened like once a weekend. So I replaced all the fuel/water separator, the fuel filter in the motor, and the fuel pump. And it still did it. Today I was at full speed and the it happened this time while running at full WOT. The motor completely bogged down couldn't get it to plain. Now for the strange part. If I put the motor in neutral it would rev up to full 9000 rpm (quick rev). While the motor is struggling to go I started to tap the electric choke and it slowly picked up speed plained out but only got to 4000 rpm. If I stopped tapping the electric choke then we would stop at 15mph. I have checked them compression check and all 4 are good.

Anybody have some advice?

 

[robert graham]

Have the carbs ever been removed, disassembled and cleaned?....could be plugged jets. A Yamaha Outboard dealer can do this for you. Best to deal with this issue, as a lean fuel mixture caused by plugged jets can burn a piston in that cylinder.

 

[SouthCarolina1]

Can someone post a link to a complete carb kit for the motor? I can't find one for that exact motor.

 

[SouthCarolina1]

Ok so I have rebuilt the carburetors. Boat takes off fine now, I can get to WOT. BUT now after 2-3 min of going around 5,000 rpm's I get a high temp. alarm. If I stay around 4,000 rpm I do not get the alarm. I just replaced the water pump and thermostats... Any ideas?