4BY2: Fatigue Cracks in Engine Cover Support Brackets

[mfreeman_1998]

Our trusty 2012 RT-27, with 1700 engine hours, recently successfully carried us 7400 miles on the Great Loop. Since returning, I've been giving the vessel a good inspection to identify those parts or systems that require repair, replacement or upgrade. In the course of the inspections I found significant stress fractures in the two brackets, on the front of the Yanmar 4BY2 diesel engine, which support the front of the sheet metal dress covers which protect the top of the engine.

The brackets were removed, repaired and replaced. I also installed new vibration isolators.

I did a quick write up of this project, including pictures, so that you can see what I encountered in case you would like to inspect your motor for a similar problem.

The write up can be found at:

http://www.sonic.net/~mfreeman/RangerTug/Brackets.pdf

 

[Diatom]

Precisely. Thanks for the writeup/pics.
Has the dress cover any function beyond aesthetics? e.g. heat shielding?
/Diatom

 

[mfreeman_1998]

If you look under the engine covers there are many components and assemblies that benefit from the protection the covers offer. I chose to reduce risk of damage by repairing the supports so the covers are 100% functional.

 

[Diatom]

Thanks. Doing likewise. Strange place for stress cracks - I'm guessing it reflects folks using the covers as a step.
/Diatom