1987 22' Sea Ray Pachanga with quicksilver shifter. The detent button to "throttle only" has suddenly stopped working. I take it to the shop for fixing along with a few other things. Has always been a reliable shop until now. After getting to the lake and realizing it still doesn't work, I notify the shop. Over the phone he says, "it must be worn out from age, need to replace the box, easier then nickle and diming yourslef for the replacement parts." The "old style box" like I have is no longer available so I have to upgrade to the new box which in turn means a new throttle handle--total cost w/o install $325. I have seen some REALLY nice offshore controls for that price. Any advise on either a fix or replacement? My quicksilver is side mounted--FYI.