Hello, I am considering buying a boat with twin Mercury Racing 540's. Does the 540 have the same service interval as the 525? Does the 540 have the same issue as the 525 with the CMI headers? What service is recommended for a 540 with 350 hours? Thank you for any information that you can supply for the 540 that will help me decide if this is the right engine package for me.

No header issues with the 540's like the early 525's had, also from what I was told at PBC the 540's aren't due for service until 500hrs.

Thank you for the information. Do you know if that would be full rebuilds at 500 hours or just valve springs, head gaskets, etc..? Does anyone know if 540's cost the same to rebuild as 525's?

Your welcome and I would give Mercury a call for more info. The customer service there is very helpful on any qustions you have.