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Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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I have a 175 sport jet (1998). The last time I took it out

Customer Question

I have a 175 sport jet (1998). The last time I took it out the throttle speed started varying wildly. It is no longer idling properly. This was never a problem before.
Submitted: 1 year ago.
Category: Boat
Expert:  Tan replied 1 year ago.

Hello. My name is Tan.

We need to start out with a spark and compression test. The compression must be 90+ psi with no more than 10 psi difference between cylinders. The spark must jump a 7/16" gap on a spark gap tester.

Then one last test run engine on a different fuel tank to eliminate the boat side fuel system as possible fuel starvation issue.

Can you do these tests?