Rough idle

[Tony Dag]

Mercury 1999, 200hp 6 pack carbs, has rough idle, runs good at high speed, any suggestions

 

[DeepCMark58A]

First, check fuel. Put in an additive that will deal with any water accumulated in the system. Check the spark plugs too. Does the motor start easily?

 

[Tony Dag]

Yes it does I'm sorry I didn't get back to you sooner I appreciate your input

 

[Dukedog]

have you made any changes to anything?.. ie: lectrics, linkages, screw settings etc... did it start actin' up on its own?.. all of a sudden or gradually?..

 

[Tony Dag]

No haven't made any changes and just did start gradually just got done seafoam in it

 

[Dukedog]

can't say for sure ona keyboard!.. probably carbs.. clean, new gaskets all three..... might be fuel eatin' at mech pump, fuel lines, filter etc.. replace all lines, filter.. kit tha pump... do comp test.. 115 or better would pass... fire on all six?.. justa few things ta start with.. do ya have an oem manual?

 

[Tony Dag]

Thank you I'll try that