Ihave a 175 johnson with a 4wire vro which needs to be replaced. can i use a 3wire vro from a 115? if so what do i do about the extra wire which is purple.
I wouldn't.<br /><br />The 4-wire is a VAST improvement over the 3.<br /><br />You're going backwards. If you do not want to buy a new 4-wire. Disconnect the whole thing and run pre-mix.