Yanmar Pleasure Boat Marine Engine Help

FUEL - Overview

Diesel fuel oil in the USA has traditionally not met the minimum cetane requirements for Yanmar engines, which require a minimum cetane rating of 45. The introduction of 'Premium' grade fuel should have changed this so use 'Premium' grade diesel where possible. Note that ' red ' diesel is dyed for the tax inspector only, it has nothing to do with the quality of the fuel. As best as one can tell, "Biodiesel" meets the requirements.

Diesel fuel standards: ( mouse over for the applicable areas )
ISO 8217 DMA
ASTM D975 Grade No.1-D or No.2-D
JIS K2204 Grade No.2, No.3 or special-No.3
BS 2869 Part-1 class-A1 or A2

At low temperatures, diesel becomes difficult to ignite and will not flow easily, making starting difficult. Select fuel oil of a cetane of 45 or greater to ensure ignitability, and use the outside temperature as a guide for selecting the proper grade to insure fluidity. Some countries make 'Summer' and 'Winter' diesel. Diesel has a certain amount of 'wax' in it. In winter the wax can solidify and block the fuel system. As this is not normally a problem in higher ambient temperatures and the cost of making ' winter ' diesel is higher than ' summer ' diesel, a refinery will make each product for 6 months at a time. Spring to Autumn for ' Summer ' and Autumn to Spring for ' Winter ' diesel. The point of mentioning this is that sometimes, at the beginning of Spring when it's still cold, the 'summer' diesel will block 2 micron filters, causing the engine to slow or even stop. My experience with this was on high horsepower engines fitted with 2 micron primary fuel filters only. Fitting 10 micron filters solved the problem.
The best thing you can do with fuel is buy it clean and keep it clean. This is not always easy to do!
Buy your fuel from the dealer with the largest turnover. This may not necessarily mean the cheapest as the cheap company may not spend money on maintaining their fuel supply systems, hence putting you at risk, although most reputable companies try hard as in this industry bad news travels very fast.
If you need to transport your fuel in containers, make sure, before you fill them, that you have looked inside to check they are clean. (My son was very helpful once, filled the containers with the water hose. 'Dada', he said, pointing proudly at what he had done, he was 2.)

Water in the Fuel?

WATER IN THE FUEL

Re-fueling from dubious sources

When you refuel from dubious sources, if it is drum stock, allow the drum to stand for 24hrs before pumping the fuel. ( Aw come on, we're cruisers arent we? ) Any water will settle to the bottom of the drum. DON'T MOVE IT or you will undo all your good waiting time. The pump should have a stand pipe so that the water and debris are left in the bottom of the drum.
When refueling, lay a chamois leather (like the one you use to clean the car) in the funnel . If water hits the chamois first, only water will pass thru and if fuel hits the chamois first only fuel will pass thru. This may be a slow process but it is faster than what happens later when you have water in the tank.

Once water is in there, how do I get rid of it?

REMOVING WATER

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