Motor question

[jgannard]

I have a friend that has a 18 ft express boat, he recently bought a mercury 150 opt max. Before it had a 115 yahama, my question is I thought u couldnt put a different motor than what u had before.

[weedeater]

Just what I understand..... you will have to change controls to match motor and make sure of hp rating on boat

[jgannard]

He never changed the controls, that's what I don't get

[weedeater]

I think he will need to change to merc control in order to have a merc work but this is just what I have heard maybe someone who knows for she's will chime in.