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Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 11052
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
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I have a 1997 44ft Carver Motor Yacht. They have ZF marine

Customer Question

I have a 1997 44ft Carver Motor Yacht. They have ZF marine gears IRM301A-2. I had a recent survey and the engine surveyor said their was transmission gear clatter only at idle speed. He said the flex plate couplers needed to be replaced. I can increase idle speed by 15-20 rpms and the noise goes away. My mechanic seems to think we just raise idle by that amount and problem solved. The engines are Cummins 450hp 6CTA8.3MTA. Present idle speed is 668 rpms. What are your I need to go to the expense of replacing th flex plate couplers?
Submitted: 1 year ago.
Category: Boat
Expert:  Tan replied 1 year ago.

Hello. My name is Tan.

The idle can be increased as it is a little low. The idle rpms go up to as much as 700. I would try this first then monitor the noise. If it gets worse then the plates will need to be changed.

Thank you.........Tan

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