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Need some help with carb adjustment, 90 Merc 2-stroke

Posted: Thu May 30, 2013 11:32 am
by cwag911
This is a friends boat with a 2000 Merc 90 hp. The carbs have been rebuilt, all fuel lines replaced and the fuel tank cleaned. He hasn't taken it out for a ride yet, but idling in his slip, about every 10 seconds or so it spits then idles fine then spits again. A marine mechanic friend thinks it's running lean. I was going to have my friend take it for a ride, then check the plugs. Any info on carb adjustment would be helpful. TIA.

Re: Need some help with carb adjustment, 90 Merc 2-stroke

Posted: Thu May 30, 2013 12:05 pm
by MPosey519
If it's just during idle, the idle adjustment screw should be on the side of the carbs. start with them 1 1/4 turns open and adjust from there.

Re: Need some help with carb adjustment, 90 Merc 2-stroke

Posted: Thu May 30, 2013 12:08 pm
by curtiscapk
Carl,

normally one and a half out....

Re: Need some help with carb adjustment, 90 Merc 2-stroke

Posted: Thu May 30, 2013 12:14 pm
by cwag911
OK, is out leaner or richer?

Re: Need some help with carb adjustment, 90 Merc 2-stroke

Posted: Thu May 30, 2013 12:16 pm
by MPosey519
richer, allowing more fuel in

Re: Need some help with carb adjustment, 90 Merc 2-stroke

Posted: Thu May 30, 2013 12:47 pm
by cwag911
Thank you

Re: Need some help with carb adjustment, 90 Merc 2-stroke

Posted: Sun Jun 02, 2013 6:19 am
by cwag911
Just an update. Richened up the carbs (1/4 turn) and it runs fine. Thanks again guys.