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Charles, Marine Mechanic
Category: Boat
Satisfied Customers: 3703
Experience:  US Navy (Ret) Certified Mercury Marine Tech with over a decade of repair experience.
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I purchased a 40' riviera with the QSC 8.3 490 HP. I was

Customer Question

Hi there. I purchased a 40' riviera with the QSC 8.3 490 HP. I was wondering what the recommended and max cruising RPMs are for those engine So?
Also it came with the Smartcraft electronics.... It appears one of the engines is not calibrated as I get different readings per I need a Cummings mech to work on these? Live in the Seattle area and would appreciate the help!
Many thanks!
Submitted: 1 year ago.
Category: Boat
Expert:  Charles replied 1 year ago.

Hello, my name is***** will assist you with this.

The rated RPM for this engine are 2600, Cummins says that the crusing RPM is 200-400 less than max. Your best fuel burn is a between 2000 and 2200 RPM. Have a look at this data sheet.

For your gauges, I will need to know if it is the SmartTach or the Engine Monitor or SystemView.

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