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Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 11078
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
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My 1996 70hp runs good most of the time but sometimes when

Customer Question

My 1996 70hp runs good most of the time but sometimes when going from 3000rpm to higher it shudders and shakes and smokes. It will stay like that for some time and then get better. Seems to be happening more often
Submitted: 2 years ago.
Category: Boat
Expert:  Tan replied 2 years ago.

Hello. My name is Tan.

This will require the use of a timing light and a friend to run the boat and check spark on all cylinders.

Do you have a timing light and someone to run the boat while we do this test?