rigged 225 on my boat with vro disconnected,(pulled the amphenol connector,plugged oil line)enginge wont go above 2500 rpm and bucks.I see a red plug that is located on the electrical contact board on port side,it seems to be there to allow a disconnect of something?is this something I should be disconnecting.I have disconnected earlier VRO's from other engines ,but,this 225 seems to have other fetures I know nothing about,like SLOW MODE.Thanks for you help.Mike