Petrol worries
The outboard maintenance article in PBO October 2018 has alarmed me. I have a 52-year-old Kingfisher 30 sailing sloop which I bought 44 years ago. This boat was supplied with a WaterMota Sea Wolf petrol engine, as many were in those days.
The engine lasted well in spite of being seawater cooled but when 30 years old it was getting a bit rusty so I changed it for a Ford Escort Mark II 1300cc petrol crossflow Kent engine which I marinised to indirect cooling. For the last 20 years this has worked well and I am very pleased with it.
The Kingfisher 26 and 30 are unusual in having twin keels that are steel fuel tanks bolted to the underside of the hull and so outside the boat. They hold 300 litres of fuel and I use less than half this during a sailing season so some petrol in there could be several years old. In spite of this my engine always starts immediately and has always been exceptionally reliable, including the time years ago I had a small leak in one of the tanks and the engine was running on a petrol/sea water mix! I am very satisfied with the engine and I wish to continue using it. Obviously I make sure I have no petrol leaks but the only tube with positive pressure is the short rubber tube between the fuel pump and the carburettor and I make sure this is in good condition.
This article suggests modern petrol deteriorates in just a few weeks and gumming up of carburettors is one of the problems that can occur. Am I really being advised to ditch several hundred litres of fuel and refill in the spring? And if so how do I dispose of the stuff? Tony Foister, Chichester Rob Day, Honda technical trainer responds: the smaller the quantity of fuel the quicker it will go off. Generally speaking a smaller cc engine (such as a small outboard) will have a smaller carburettor and a smaller carburettor float bowl along with smaller jets where the fuel passes through. These types of engines are more vulnerable as the fuel deteriorates sooner in the carburettor compared to larger cc engines like yours. The deterioration can cause the carburettor jets and other components to become partially blocked causing poor running or non-running in the worst case.