Yanmar Marine Engine Owner's Group - Repair and Discussion
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The owner of the sailboat is Mr. Michiel van Hartesveldt a mechanic who has been working for Cummins engines for more than 17 years, an experienced man who doesnât hesitate to help other sailors in the several groups of Yanmar engines maintenance such as:
Yanmar Marine Engine Owner's Group - Repair and Discussion
ATLANTEL SAIL 902 was built by a shipyard called Polymer based in Lorient France. The Sail 902 sailboat is a habitable cruising monohull, designed by naval architect Guy Saillard at the Atlantel shipyard, that measures 8.5 m long. Production started in 1977 and ended in 1985, and two versions were produced: a racing and a cruiser version. It was a strong competitor to the Bénéteau First 30. Originally, it was equipped with a Renault engine. But, in this case, it was repowered using the legendary Yanmar 2YM15.
The Yanmar 2YM15 is a marine diesel engine produced by the Japanese company Yanmar Co., Ltd. This engine is part of Yanmar’s extensive line of marine engines designed for use in sailboats and small powerboats. The 2YM15 is known for its reliability, efficiency, and compact size, making it a popular choice among boat owners and builders.
The engine’s 2-cylinder design made it suitable for smaller vessels where space and weight considerations were important. The 2YM15 is known for its durability and ability to withstand the harsh marine environment, including exposure to saltwater and continuous use. While newer models and technologies have emerged in the marine engine market, the 2YM15 remains a classic choice for those who appreciate its simplicity and dependability.
July 2022, Michiel van Hartesveldt, with over 20 years of experience as a diesel technician, had always prided himself on his ability to troubleshoot and solve any engine-related problem. However, he found himself facing a perplexing issue aboard his sailboat.
The problem was persistent vibrations that occurred when the Yanmar 2YM15 engine was running between 1000 and 1500 RPM. Michiel had already put his extensive knowledge to good use. He’d replaced the fuel and filters, double-checked the engine alignment, inspected the shaft, and even balanced the variable-pitch propeller with meticulous care. Every component had been scrutinized, from engine mounts to gearbox oil and air filters. He’d painstakingly ensured that all bolts were secure and even examined the injectors, which were operating perfectly with a spray pattern of 130 bar at 5-10 degrees.
He turned to the online sailing community, seeking advice and wisdom from fellow sailors and mechanics who had faced similar challenges, making the post below:
Fellow sailors and diesel enthusiasts shared their experiences and suggestions.
There are several factors that can also affect the stability. Pointing Michiel to the below article:Â
This text provides guidance on improving engine stability in recreational boats or sailboats. It addresses several key factors that need to be considered:
Engine issues like damaged pistons or injection valves can lead to poor engine performance and excessive movement. Addressing these problems is essential for achieving smooth engine operation.
The shaft’s condition should be checked to ensure it is not damaged or warped. A bent shaft can lead to misalignment and generate excessive engine movement, potentially causing water to enter the boat and premature deterioration of components.
The cutless bearing, due to the shaft’s rotation, can wear out. This wear can result in shaft misalignment, lateral movements, and erratic rotation, leading to vibrations and engine movement.
Proper alignment of the shaft with the stern hole is crucial to prevent rubbing and water leakage. Misalignment can lead to water entering the boat, which should be corrected using various methods.
Engine mounts play a critical role in absorbing engine movement and preventing vibrations from transmitting to the hull. Over time, these mounts may lose their elasticity, causing shaft misalignment and reduced performance. It is recommended to replace them every four years or after 1000 hours of use.
Achieving proper alignment between the engine and the shaft is essential. The engine should be adjusted to fit the shaft, rather than the other way around. This can be achieved by adjusting the leveling nut of the mounts, with caution not to raise it too high. If raising the engine higher is necessary, shims can be used.
By addressing these factors and ensuring proper maintenance, boat owners can enhance the stability and performance of their boat’s engine, leading to a smoother and safer sailing experience.
The below video shows the Ellebogen mounts in operation, in the current setup. The results can be considered as acceptable, but Michiel was not satisfied with the results.
Remachining the engine: Block, pistons, rings, liner honed rebuild cilinder head.
New engine bed
Python Drive
Michiel overhauled the engine and modified it with an exhaust riser attached to the heat exchanger. A small hole inside the elbow has sprayed some water to cylinder 2.
He also discovered a noise from the flexofold propeller, so he took the boat out of the water again.
New Ellebogen mounts. Based on the importance of the case we decided to send new mounts, with an improvement on the damping coefficient using a synthetic compound for this purpose.
Based on our experience on this 2YM15 engine, it is our belief that it is difficult to improve the result.
We thank Michiel for his work and dedication. He is a top class Ellebogener.
