How to adjust idle on Merc 15hp 4 stroke?

[PriceTR24speed]

2006 Mercury 15hp 4 stroke. Installed a new carburetor in the motor starts and runs great. The only issue is the idle is way too high. How do I adjust the idle on that model motor?

Thanks

 

[FuzzyGrub]

The procedure is usually covered in the operation manual. If you don't have one, go to Mercs website and download. Best to use serial number. Merc Op Manuals

 

[PGRChaplain]

A Vacuum Leak will cause high idle as well.

 

[PriceTR24speed]

I finally received the service manual I had ordered. It’s amazing how simple things are when you read the instructions.

Step 1 - verify/adjust throttle linkage.
Step 2 - with motor running turn Idle adjustment screw to set idle - note works best if done with the motor in the water.

 

[FuzzyGrub]

Most that I've seen, want it to be in the water, and warmed up, so it is adjusted with the back pressure produced by the water. Some want it in neutral, others in gear, while adjusting to an rpm.