Yanmar 3YM30 22HP USED

Sometimes an engine (3YM30 engine) manufacturer will get it right. The engine offers good natural balance, torque, and fuel efficiency. qualities that both a good industrial and marine engine should have.

The 3YM30 is the Yanmar series’ most powerful three-cylinder indirect-injection marine engine. The indirect approach is putting fuel into a tiny, snail-shaped precombustion chamber before releasing it into the combustion chamber. This enables direct-injection engines, unlike small mechanically injected diesel engines, to comply with emission laws.

Hand starting is not an option since indirect-injection engines have much higher compression ratios than comparable power direct-injection engines. The previous indirect-injection 3YM30 engine was equipped with hand cranking in addition to the starting motor, which was overly optimistic given the engine’s 23:1 compression ratio and was retired roughly ten years ago when the 3YM30 engine was introduced to the Australian market. However, Yanmar has wisely removed all hand-starting capability since it doesn’t want the owners of its engines to get hernias or strained backs. Keep the bilge dry since electric starting with glow plug preheat is king!

YANMAR 3YM30 MARINE ENGINE

Here comes the dull part. The 1115cc OHV engine in the Yanmar 3YM30 engine produces 28.6 horsepower at 3600 rpm or 26.9 horsepower continuously at 3490 rpm. The engine has two valves per cylinder and gear-driven pushrods. The engine is able to achieve good combustion chamber efficiency because to the 76mm cylinder bore and 82mm cylinder stroke. At 2000 to 2500 rpm, the maximum torque production is 69.5Nm. The engine may run for up to 500 hours a year with a maximum of 5% Wide Open Throttle operation, according to its A rating.

The Yanmar 3YM30 engine has a centrifugal freshwater circulation pump and a positive displacement saltwater pump, both of which are located at the forward end of the engine for convenience. It is freshwater (heat exchanger) cooled. The maximum output of the typical voltage-regulated alternator is 60 amps, and an 80 amp

The Yanmar 3YM30 engine is fairly small for its output, measuring 716mm long, 462mm wide, and 618mm high when complete with a mechanical cone-clutch gearbox. The mechanical box comes in a variety of reduction gear ratios, but I prefer the 2.62:1 ahead and 3.06:1 astern ratio box for the majority of yachts because it provides more power astern. The combined dry weight of the box is 133 kg.

Avoid attempting fast shifts from ahead to astern without letting the engine idle first because the SD20 saildrive version only has a dog clutch and 2.64:1 ratios ahead and astern. The whole weight increases to 154kg.

Every year, oil and filters should be changed, and the best oils for tropical climates are SAE 15W40 or 10W30.

3YM30 ENGINE ON THE WATER

Getting a hull to test diesels can be extremely challenging at times, but happily, my friend Theo has twins in his Lagoon 380 cruising cat. The usage of saildrive models leaves plenty of room for the installation of Gori folding props because they are located aft of the rudders. For motorsailing or motoring in calm conditions, these straightforward yet clever designs offer an overdrive facility to maintain the proper amount of engine load. 3YM30 engine

The engines had logged roughly 1000 hours each when I tested them on a delivery journey from Brooklyn up the Hawkesbury River to Lake Macquarie, with the main issue being a leaky exhaust gas manifold on one of the 3YM30 engine.

Both engines started promptly whether they were hot or cold, produced no oil or exhaust smoke, and were exceptionally quiet and smooth for three-cylinder engines over the whole rpm range. The 8.5-tonne hull was readily swung in its own length using the one ahead/one astern approach due of its enormous 22-foot beam.

We were able to maintain engine load at all rpms after mastering the technique for engaging overdrive. This was crucial for the 3YM30 engine because it needs to be operated continuously at or above 2500 rpm to prevent cylinder bore glazing due to inadequate load. The 16.5 x 12in three-bladed propellers were logically tiny enough to enable the engines to run at 3700rpm at full throttle without the overdrive. The prop pitch measures roughly 14 inches while in use.