When are 1991 Mercury 115 2+2 cylinders 3 and 4 supposed to cut in?

justchecking

Petty Officer 2nd Class
Joined
Oct 1, 2010
Messages
152
Ran it on the lake yesterday for first time after the rebuild. I noticed that one cylinder cuts in at about 2000 RPM and the second one at about 2500. Is that normal? Does the lower one cut in first?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,797
Re: When are 1991 Mercury 115 2+2 cylinders 3 and 4 supposed to cut in?

The 2 bottom cylinders should start operating at about 1800 / 2000 RPM.-------Lower one does not start working first.-------It depends on airflow through the carburetors.
 

justchecking

Petty Officer 2nd Class
Joined
Oct 1, 2010
Messages
152
Re: When are 1991 Mercury 115 2+2 cylinders 3 and 4 supposed to cut in?

Maybe I'll ground one of the sparkplugs to see which one is cutting in last. I did rebuild all carbs and know the float heights, etc are all the same per spec.
Thanks for the feedback.
 
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