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Charles, Marine Mechanic
Category: Boat
Satisfied Customers: 3976
Experience:  US Navy (Ret) Certified Mercury Marine Tech with over a decade of repair experience.
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2006 90 HP mercury stalls at idle. It runs great at all

Customer Question

2006 90 HP mercury stalls at idle. It runs great at all other speeds. I adjusted the idle screw and that worked for a few hours but then it started stalling again???
Submitted: 1 year ago.
Category: Boat
Expert:  Jason replied 1 year ago.

Hello my name is ***** ***** am I speaking with?

All Mercurys are cataloged by serial number, can I start by getting that number so that I can run it and see exactly which engine you have.

Next, what is the history on this engine, have you ever personally seen it idle correctly?

Customer: replied 1 year ago.
let me dig it up. my name is ***** ***** I've owned the motor since new
Expert:  Jason replied 1 year ago.

Hi Paul, okay i'll be here.

Customer: replied 1 year ago.
Expert:  Jason replied 1 year ago.

That is not the serial number, the serial number is ***** a tag on the clamp bracket, starboard side. Click this link below to pull up a picture.

Customer: replied 1 year ago.
Expert:  Jason replied 1 year ago.

Okay this engine is EFI. It will have to get hooked up to a scan tool in order to figure out why it's not idling. Did you have any questions that I could answer?

Customer: replied 1 year ago.
Expert:  Charles replied 1 year ago.

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

With the engine not idling, but running ok, the problem is probably going to be a sticking IAC valve. It is located near the top of the intake. When you turn the engine off, you should hear it click several times. If it is not, remove the valve, then clean it to see if you can get it unstuck. If it will not, it may be bad.