Chasing a High Idle on My MerCruiser Four Point Three
#1
Thread Starter
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Joined: Nov 2025
Posts: 10
Likes: 2
I have a Tahoe with a MerCruiser four point three that was rebuilt with a fresh long block. The boat runs strong but it keeps a high idle and gives off a fuel smell at low speeds. I am learning as I go and I am trying to understand what usually causes this on these motors.
If you have dealt with similar symptoms or have advice on what to check first please share your experience. I want to get this boat fully dialed in before the next run on the water.
If you have dealt with similar symptoms or have advice on what to check first please share your experience. I want to get this boat fully dialed in before the next run on the water.
#2
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Joined: Nov 2009
Posts: 4,197
Likes: 500
From: KY
Remove throttle cable, check that the carb butterfly is fully closed. Adjust barrel nut so that it just slides on to carb and barrel retainer. Remove cable and rotate barrel nut one more full turn away from carb and reinstall




