Yanmar Chosen for Trawler’s Two Repowers – 200,000 hours apart

The Petuna Endeavour is a commercial deep sea fishing trawler, a vessel with a long and proud history. Repowered with a Yanmar just four years into her life, some 30 years later the Petuna Endeavour was again repowered with the Yanmar.

Petuna Endeavour was built in Launceston in 1979. The original engine installed into the 23.8m, 190-tonne trawler was a classic English brand which proved to be inappropriate for heavy marine use. With just four years of fishing behind her, the heavy seagoing trawler was repowered in 1984 with a Yanmar S165 marine diesel engine. This was a slow revving 1250 rpm, six cylinder engine which delivered 550hp with masses of torque. Powered by the Yanmar S165, Petuna Endeavour pressed on for decades of reliable service.


Today, Petuna Endeavour operates in the southeast of Australia, with between 2-3 months a year in Queensland waters. In 1995 Petuna Endeavour was converted into an auto liner, one of only two such equipped vessels in Australia.

With the Mustad auto bait hooking system capable of setting 15,000 hooks a day, the capability of this long liner is second to none. Petuna Endeavour fishes mostly for Pink Ling and Blue Eye Trevally with 80% of the catch destined for the domestic market. Each time the Petuna Endeavour heads off to sea, the trawler carries a skipper plus four crew with each trip around a week in duration depending on the markets and sea conditions.

Phil Hough, the skipper of Petuna Endeavour of 16 years standing, has nothing but praise for his vessel. “This can be tough and at times dangerous work,” Phil Hough said.

“The Petuna Endeavour has been through some wild and very rough seas, yet has never flinched once. In the engine room, the Yanmar S165 performed  faultlessly and we logged up 200,000 engine hours over 30 years, an outstanding achievement for the Yanmar brand.”

At 1150 rpm the Yanmar S165 was pushing the Petuna Endeavour along at a steady 8 knots with fuel burn at 55 litres per hour. The trawler carries 35,000 litres of fuel and has catch tanks with a combined capacity of 55 tonnes. Although there was nothing major wrong with the Yanmar S165, the owners decided that it was time to update and re-power Petuna Endeavour. In spite of the stunning record with the Yanmar S165, the owners undertook detailed research of competitive engine brands.


As part of the buying process, the owners and skipper went to Melbourne to personally check over the Yanmar models. Power Equipment, the authorised Yanmar distributor, impressed greatly, not only with their modern facility but the people themselves responsible for sales, technical support and parts supply. Yanmar stood out as the preferred brand and a brand new Yanmar 6AYM-WST was purchased.

The repower was performed by Rogers and Lough marine engineers in Brisbane. Due to the configuration of the hull and the location of the engine room, an access hole was cut into the bottom of the steel hull. The trusty Yanmar S165 was removed through the hole and the new Yanmar 6AYM-WST with new Yanmar YXH240L transmission was winched into place.

The Yanmar 6AYM-WST is a six-in-line cylinder engine with a displacement of 20.39 litres and a rated power output of 659 mph (485kw) at 1,900 rpm. This Yanmar model is noted for its strong performance, low fuel consumption and low emissions. The versatile Yanmar 6AY Series is extensively used in many applications including heavy displacement work boats but also in many high-speed applications such as passenger ferries, patrol craft and fishing boats like Petuna Endeavour. A key attribute of this model Yanmar engine is the high torque output, particularly in the middle and high-speed ranges for reliable work performance at sea.

Following the six-week re-power project, Petuna Endeavour was put through extensive sea trials. Fitted with a 5.36:1 reduction ratio and retaining the original Mikado 66” x 54.4” four blade prop, the Petuna Endeavour could comfortably steam at 1550 rpm for a speed of 8.8 knots. Fuel burn remained the same.

“The repower gave us a 10% increase in speed for the same fuel consumption,” Phil Hough said. “When we need to get back to port in a hurry or beat the weather, we can run at 10.5 knots at 1800 rpm.”

“From the helm, the enhanced performance of the Yanmar 6AYM-WST is easily felt. This engine delivers a massive amount of torque and it’s good to have all that extra grunt on hand.”
Typically Phil Hough will run the Yanmar 6AYM-WST engine for between 14 and 18 hours a day. Apart from the runout and back to port and then shifting from one fishing ground to the next, there is a lot of idling and constant gear shifting.


“The mechanical fuel system on the Yanmar engine is ideal for our application. Plus, the 500-hour service intervals is a big bonus and we are able to change filters and oil while we are away at sea if necessary.”

“Our experience with Yanmar has definitely been a positive one,” Phil Hough concluded.