1996 Mercury 115 Dies at Slow Speed
Posted: Sat Apr 22, 2023 4:23 pm
My 1996 MERCURY 115-HP engine [later clarified to be a four-cylinder in-line engine in which only two of the four cylinders operate at low speeds, a design known as the 2+2 engine] suddenly shuts off at less than 2000 rpm. It doesn't spit and sputter. It dies suddenly as if it was switched off. Most times it will restart and will run for several seconds to a few minutes before it dies again. Sometimes it will not restart no matter what I do. I have to wait an hour or so before it will start up again.
If I successfully get the engine running and the boat on plane, the engine runs fine at speed.
On April 21, 2023 the engine ran for many miles at WOT and it never missed a beat. As soon as I got near the landing and brought the boat off plane and the rpms got below 2000 it died again.
I've owed the boat for ten years. I've never had any major problems. Just regular maintenance items. It's always run like a sewing machine.
Q1: what is a likely cause of the problem with the engine stalling at low speeds?
If I successfully get the engine running and the boat on plane, the engine runs fine at speed.
On April 21, 2023 the engine ran for many miles at WOT and it never missed a beat. As soon as I got near the landing and brought the boat off plane and the rpms got below 2000 it died again.
I've owed the boat for ten years. I've never had any major problems. Just regular maintenance items. It's always run like a sewing machine.
Q1: what is a likely cause of the problem with the engine stalling at low speeds?