Yanmar sterndrives win over Aussie boatbuilder


The first pair of Yanmar’s new ZT350 diesel sterndrives has been installed to an Australian-built boat, the luxury Sea Quest 3600 Sports Bridge, according to the engine’s local distributor Power Equipment.

John Young of Sea Quest has reportedly said the new model Yanmar ZT350 and Sea Quest 3600 are an ideal match.

“At Sea Quest we strive to deliver the most modern and intelligent technology in the engineroom for our Sea Quest customers,” Young said.

“Our selection of the new Yanmar 6BY2-260 / ZT350 package was made after significant research, and now that we have concluded extensive sea trials with Yanmar prior to handover to our customer, we are absolutely delighted with the outcome,” he said.

The Sea Quest 3600 is described as a big, beamy luxury cruiser, and its sportsbridge configuration determines that a transverse bunk is slotted in under the helm station, the consequence of which is a more compact engineroom. This is where the modest installation envelope of the Yanmar 6BY2-260 / ZT350 engine really comes to the fore, said Power Equipment.

The Yanmar 6BY2 engines are said to be close coupled to the ZT350 transom assembly, fitting neatly alongside one another with readily available servicing points. A big feature of the engineroom, said Power Equipment, is that the entire rear (teak laid) cockpit floor is raised on hydraulic rams to provide unsurpassed access to the engines.

“Quite apart from the lean fuel consumption, low noise and lack of diesel smoke offered by the new common rail equipped BY2 series, we are won over by the new ZT350 hydraulic clutch design that makes gear shifting smooth and quiet,” Young said.

Power Equipment said the new hydrodynamic ZT350 Sterndrive from Yanmar boasts a multi-plate hydraulic clutch that provides a positive and smooth gear change combined with quiet operation. The inclusion of precision forged gears brings sterndrive durability to a whole new level, added the distributor, while two counter-rotating propellers are used to maximise acceleration and enable tight-hold tracking in rough conditions.

When viewed from the bank, the sprightly performance of the big Sea Quest cruiser belies the size of the boat, said the distributor adding, that from the stem to the rear of the boarding platform, this is almost 13m (42ft) of boat. The twin Yanmar 6BY2-260
/ ZT350 packages throw the 6500kg Sea Quest boat up onto the plane more like a skiboat, Power Equipment claims.

At wide open throttle the Yanmar engines peaked at 4200rpm for a reported speed of 34kts, while an optimum cruise speed was achieved at 2800rpm with a speed of 17kts and fuel consumption of 19.3lt/h per engine. These performance figures, issued by the distributor, were recorded with a fuel load of 850lt of fuel and 330lt of water.

“This new ZT350 sterndrive is a breakthrough product for Yanmar in Australia,” said Power Equipment National Marine Sales Manager, Michael Blair.

“While we have already supplied quite a number of our ZT350 sterndrive units for re-power use (both single and dual-engine configurations) and several new single-engine installation’s in Australian boats, the Sea Quest is our first dual-engine installation in a new Australian-built boat. The feedback by John Young in his Sea Quest 3600 echoes what we are hearing from other Yanmar ZT 350 sterndrive owners, so we are confident of an exciting future with this new product as we continue to roll it out in the local marketplace,” he said.

Power Equipment said the Yanmar ZT350 sterndrive is designed for the existing Yanmar range of both the 4BY2, 6BY2 and the 6LPA Series of diesel engines, which cover the power range of 150hp to 315hp.