Adjusting a 1960 Evinrude 40 Carburator

[mike]

" I want to adjust my carburat

" I want to adjust my carburator but am not sure of the best way to go about it.I think it is running rich ,and is using alot of gas,and coughing at lower rpm.Does any one know what adjustment screws are used and the steps I should follow while doing the adjustment.The engine runs pretty good right now and I may be at peak performance for a 40 year old motor,but I think it could benefit from some air.Thanks in advance for any help. Mike "

 

[joereeves]

"Mike.... The top adjustable n

"Mike.... The top adjustable needle valve is for the slow speed (idle) adjustment. The bottom adjustable valve is of course for the high speed adjustment. Be sure to make a note as to where these adjustable valves are set in relation to being gently seated... then gently seat the high speed valve, then back it out one (1) turn. Gently seat the slow speed valve, then back it out one and one half (1 1/2) turns. Start the engine (yes, it will run pretty lousy right now) and set the throttle whereas the engine will stay running. Now in segments of 1/8 turn, start turning the (top) slow speed valve in. Wait a few seconds between movements of the valve for the engine to respond. As you continue to turn the valve in, the rpms will increase. Lower the throttle (rpms) to a point whereas the engine will continue to run without stalling. Continue this adjustment until you hit a point where the engine will either spit back (sounds like a small backfire) or it starts to die out. At that point, back out that adjustable jet about 1/8 to 1/4 turn. At some point in that back out adjustment, you'll find the best idle setting.

Now, the high speed adjustment. In the water, in gear, at wide open full throttle.... slowly, a little at a time, turn that (bottom) high speed adjustable valve in. As you do, the rpms will increase (keep the throttle at full throttle). You will hit a point whereas the engine will start to die out. When you hit that point, back off that valve approximately 1/4 turn (find the smoothest setting). It's always been within that 1/4 range of turning out.

Joe

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[mike]

" Thanks Joe It sounds like a

" Thanks Joe It sounds like a piece of cake ,will be trying this tommorow if the weather holds up. "