setting Low Speed Jets

[timmytes]

i have a 1999 125 merc. just rebuilt the carbs and want to adjust the low spped jets on the two top carbs. if i start them both at about 1 and 1/2turns, when i go to adjust them do i turn them in and out the same on both, or should they be adjusted seperately. how can you tell which one needs be turned in and which one out?<br /><br />thanks

 

[WillyBWright]

Re: setting Low Speed Jets

Turn them both the same, otherwise you're trying to compensate for the lean one by richening the other. Do it in the water in gear and warm. Get it running real smooth to where any leaner starts to sneeze and die, then open them 1/4 turn.

 

[DHPMARINE]

Re: setting Low Speed Jets

tim and willy <br /><br />Good advise.You can adjust one carb,then the other.Is this what you are asking?<br /><br />DHP

 

[emckelvy]

Re: setting Low Speed Jets

With the boat in the water, engine warmed up and in fwd gear, you can individually tune each carb for smoothest and fastest idle. The motor will speed up as you turn an idle screw in (lean) until it "sneezes" as described in a previous post. It'll slow down and "burble" if it's too rich.<br /><br />Once you find the best, fastest, smoothest idle point, this adjustment will probably make it bog upon acceleration. At this point, adjust all 3 idle screws equally CCW (rich), 1/8 turn at a time until it doesn't bog. <br /><br />The idle may be a tad lumpy after the final adjustment, but that's about as good as you're going to do on these old Beasts! You may have to adjust tweak idle speed stop, such that the motor's running fast enough to maintain a stable idle in gear.<br /><br />Once you have it tweaked in, she should run real strong for you.<br /><br />HTH........ed