# Idle speed



## eightwt (May 11, 2017)

30 hp 2 stroke merc tends to stay at too high idle after running at speed making shifting rough, especially at the dock. Also , in neutral it will gradually increase revs and then make a little popping noise and then drops revs. Then keeps repeating the same. While flushing can hear and see pop coming from prop exhaust. Almost like it builds pressure and then spurts it out, if that makes sense. Thanks for any ideas.


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## yobata (Jul 14, 2015)

Have you tried adjusting the idle jet screw? Or at least making sure that both (2 cylinders I assume) are set at the same mark?

Had the same issue with my 25hp 2 stroke yamaha - I screwed them all the way down, then backed out to original manufacturer's specs of 2+- 3/4 turns and it fixed this issue for me...


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## Guest (Mar 26, 2019)

Sounds a little lean to me.


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## Finsleft258 (Oct 7, 2018)

Boatbrains said:


> Sounds a little lean to me.


^^^^^This!!!

It's lean pop. It means your carb is dirty or not tuned properly. Get it repaired, it's not good for the engine.


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## Dadvocate (Jun 26, 2011)

After checking what Yobata posted. Pull the fuel bowl drain screws out and see if any crap comes out besides clean fuel. My next step would be carb cleaning.


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## eightwt (May 11, 2017)

Boatbrains said:


> Sounds a little lean to me.





Finsleft258 said:


> It means your carb is dirty


Thanks guys. Should I try getting it richer before cleaning or clean the carb first?


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## Guest (Mar 27, 2019)

Yeah, try adjusting. Run motor, allow to warm up. Adjust idle pilot 1/4 turn in or out. Sound/run better? If so leave it. If it got worse, you went the wrong way so go back 1/4 plus 1/4 and see how that does. After making an adjustment give it a minute or three to stabilize before making anymore adjustments.


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## eightwt (May 11, 2017)

Boatbrains said:


> Yeah, try adjusting.


My part schematic shows two, one labeled Idle Needle and one named Screw Idle Speed. Which one? 
Thanks
Would love to attend maintenance gathering.
Hope the build is going well


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## Guest (Mar 27, 2019)

Go with idle needle.


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## eightwt (May 11, 2017)

Ended up adjusting the idle needle out 3/8 turn and it seems to have eliminated the sneeze and sounds somewhat smoother. Hopefully will be taking out in a few days and will see how she runs in use. Thanks again everyone, learned from your advice.


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## eightwt (May 11, 2017)

Ran her yesterday. No sneeze, ran smooth. Definitely could see increased oil usage from reservoir.


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