[mark1rev]

hello i have a 2hp mariner/yamaha outboard, model is 2B
6A1 078449. i have changed the head gasket and gaskets that seperate the exhuast/water as it was letting in water into the cylinder. now thats sorted out i am wondering what the idle screw at the side of carb is ajusted to ? and also what the small pipe behind the carb does it goes from top of behind carb to underneath behind carb ? and what year it is ? can the small pipe if bloced stop the engine starting you can just see pipe in pics [IMG]http://http://s260.photobucket.com/albums/ii13/mark1rev/?

action=view&current=DSC09326.jpg[/IMG]
http://s260.photobucket.com/albums/i...t=DSC09324.jpg

[Yepblaze]

I see a screw that appears to be a slide stop idle speed setting screw. It would be set at desired speed. A basic setting might so that the slide when viewed in from the end of the carb opening is lifted about 1/16 inch or so from bottom.

Don't see a small pipe, perhaps you finger was in the way.

[mark1rev]

the pipe is left of my finger under the other screw its like a hose with a metal fitting to hold it tight pipe is about 6 inches long

[mark1rev]

another pic of pipe

http://s260.photobucket.com/albums/i...DSC09328-2.jpg

[mark1rev]

any help please ? even year