replaced spark plugs still runs rough from 1900 rpm to 2150 rpm

[haroldpaul]

just replaced spark plus on 2011 gts does same thing.runs rough from 1900 to 2150.from 1600 to 1850 runs smooth& from 2200 & up fine

 

[red2blue]

just replaced spark plus on 2011 gts does same thing.runs rough from 1900 to 2150.from 1600 to 1850 runs smooth& from 2200 & up fine

Mine idles between 1850-2100...so.....

You made sure to remove the cap from the plugs?...threads on top only?

Fresh gas?

Were your latest numbers in the water or on a trailer?

 

[haroldpaul]

Thats in water runs great otherwise. 47 hrs on ski.

 

[haroldpaul]

yes i removed screw caps off top of plugs

 

[AircraftDoc]

New spark plugs can be bad if the kid at the counter drops them. Old fuel?? The rough running engine at 1,900 could be a impeller to engine imbalance. Check the leading edges of the impeller. Then the maybe the cover for water and re-grease it.