Jump to content
Sign in to follow this  

Engine Idle Speed Adjustment(Boat-In-The-Water) Mercury I/O

Recommended Posts


DO NOT leave helm unattended while performing idle speed adjustment. Boat MUST BE moving forward (not tied to the dock) when setting idle speed.

Engine should idle at 650-700 RPM with boat in the water, drive unit in forward gear and engine at normal operating temperature. If idle speed is incorrect, proceed as follows:

1. Disconnect throttle cable from carburetor. Be careful not to lose spacer on anchor stud and spacer and bushing on throttle lever screw.

2. Start engine and place remote control lever(s) in forward gear, idle position. Adjust idle speed adjustment screw to obtain recommended RPM.


Throttle cable brass barrel MUST BE adjusted properly (in next step). Over-adjusting barrel in the other direction will exert excessive pressure on throttle lever, which could cause damage to carburetor linkages.

3. Stop engine. Readjust cable brass barrel (to compensate for throttle lever movement) and reinstall throttle cable. Be sure to tighten attaching nuts.

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Create New...