90Hp smoking really bad at high speed

[Crappiefishing]

I have a 94 90hp Mariner outboard motor that smokes really bad when I get up to about 15mph and over. It's ok when I am at low speeds or just starting the boat up just seems to smoke at high speeds. Anyone have any suggestions. Thanks

 

[studlymandingo]

Re: 90Hp smoking really bad at high speed

4 stroke or 2 cycle? If 2 cycle, do you premix or use oil-injection?