78' mercury mariner carbs- - jets??

[Preston]

Can anyone give me a sight where I might locate the main jets for this particular motor: 78 merc model 1400, 140 H.P. ? I currently have .0785 maines and would like to drop to a .077 or .076. she is running too rich at 4200 feet altitude. Any help would be appreciated. Thanks I-Boats participants-you have all helped me tremendously!!<br />Preston

 

[Hooty]

Re: 78' mercury mariner carbs- - jets??

Hey Preston,<br />A .002" reduction in size looks about right. I don't have any Mercury data but I do have an OMC chart and they drop .002" for operation at 3,000' - 6,000' above sea level for a 140hp engine.<br />Hope this helps.<br /><br />c/6<br /><br />Hooty

 

[petryshyn]

Re: 78' mercury mariner carbs- - jets??

Does this help?

<br />