carb adjustment

kenny45

Cadet
Joined
May 13, 2004
Messages
6
can anyone tell me how to properly adjust the carb linkage on my 1975 evinrude 40 hp motor?? thanks in advance.
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: carb adjustment

Hey Kenny....the adjustment is a little hard to explain if ya' don't have a manual....but I'll give it a shot.<br /><br />What ya' gotta worry about is getting the timing in sync with the throttle plate in the carb. Look right behind the carb and you should see a roller. This rides against the cam which is attached to the "magneto" plate under the flywheel. If you operate the throttle (motor not running) you will see how the cam rides against the roller which in turn pushes open the throttle plate.<br /><br />Now....look on the cam and you should see a hash mark...a little line in the cam. The idea is, when this line is dead center on the roller, the throttle plate should just start to open. Watch the roll pin on the port side of the carb and when it starts to move, the roller and hash mark should be lined up. (now I gotta go from memory....spooky) If they don't line up, on the starboard side of the carb attached to the linkage there should be a screw to losen a little and adjust the roller till the alignment is made.<br /><br />Next, adjust the wide open throttle plate adjustment. Running back from around the roller area you will see a long rod running to the rear of the engine just under the flywheel. This rod is what finally pushes open the throttle plates to WOT. Shift the engine in gear (while turning the prop) and advance the throttle to WOT. Look down the throat of the carb and see if the throttle plate is level. This is good. You can also look at that roll pin on the throttle plate shaft (the one I mentioned before) and if it's against the throttle stop, your OK. If you need to adjust it a little, back up on that long rod there is and anchor with a screw to set it to the rod. Make your adjusments here till WOT on the throttle plate is achieved.<br /><br />That's all there is to it. Yeah....I know....clear as mud. Take your time and look at the workings and it should become clear. If all else fails.....get a manual and read it.<br /><br />Keep us posted....thanks.
 
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