WATER-COOLED ENGINE AND SMALL PLANING BOAT FURNISHED WITH IT

摘要

PROBLEM TO BE SOLVED: To lower engine speed without depending on partial flame-out driving in the case when cooling water does not normally flow to a water-cooled engine. SOLUTION: Engine speed is detected by a tachometer 34 and pressure of cooling water W in the inside of a cooling water passage is detected by a pressure sensor 35 on a water-cooled engine 4 furnished with the cooling water passage 20 having an intake port 23 to take in the cooling water W from outside and a discharge port to discharge the cooling water after engine cooling outside. Ignition timing of an ignition plug is lagged by a lag means 38 at the time when detected cooling water pressure is lower than an allowable value to change in accordance with engine speed. Consequently, engine speed is automatically lowered when the cooling water W does not smoothly flow to the engine 4.