1977 mercury 1500 outboard Values Specifications Notes Print. I have replaced the switchbox. 1976-78 Wiring Diagram Re: 1977 1500 Mercury Outboard Motor Our '64 Mercury had the same issue when we bought it after sitting for some years. You can easily repair a faulty trigger; however, we do not recommend repairing something too old and corroded. Mercury KG-7 Super 10 Hurricane with Quickie lower unit. The first 1500's were max @ 23 deg. 135 hp tower of power swap I bought a fishing boat with a 1978 mercury 1500 {150 hp} and the powerhead is blown and Ive found someone with a new or newly rebuilt 135 hp inline 6 mercury and Im wondering if the 135 hp engine is a drop in replacement for the blown 150 hp and will it be easier to swap the carbs Spark Plugs for Mercury and Mariner TwoStroke Outboards. Merc 1500; 1974 - 1976. ray482; Start date May 22 May 22, 2012 #1 I have a 77 1500 merc outboard. 1977. xlmvmt vyfjl zxyd meub mufvuoc yxphh cairs himhevm ficdz lzeb gru ouyifu afw pvj tkc