setting carbs on 59 evinrude

Joined
Mar 20, 2003
Messages
11
Any hints on setting the low idle mix screws?Also,I took out the thermostat,the heads are just a little warm to the touch.Is this ok?50hp
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: setting carbs on 59 evinrude

The thermostat must be installed in that engine, otherwise it will run at the incorrect temperture which will result in piston/cylinder wall scoring etc.<br /><br />The correct procedure for adjusting the two barrel downdraft carburetor is as follows:<br /><br />(Carburetor Adjustments - Older V/4 Downdraft Carb)<br /> <br />NOTE: The early model downdraft carburetors incorporated "Adjustable High Speed Jets". The later model downdraft carburetors used "Fixed High Speed Jets". Follow the below instructions accordingly. If you do not have adjustable high speed jets, ignore those paragraphs pertaining to same.<br /><br />Lift the center High Speed Control lever and turn it so that the point faces forward, resting on the high ridge. This will disengage the lever control gear from the individual high speed jets (slots). Have the slow speed needle valve knobs installed upside down so that they can be turned without encountering any obstruction.<br /><br />Gently seat each of the High Speed needle valves, then back each one out one (1) turn. Gently seat each of the Slow Speed needle valves, then back each one out one and one half (1-1/2) turns. NOTE... have the jam nut on the s/speed needles snug so that viberation won't have any effect on them, but loose enough so that you can turn them without a great amout of effort.<br /><br />(High Speed)<br />With a reliable person at the wheel, and one kneeling in front of the engine, start the engine (yes, it will run lousy with the above initial needle valve settings), put it into forward gear, and apply full throttle. Start with the High Speed adjustment on the left using a screwdrive that properly fits the slot.<br /><br />(High Speed Adjustments)<br />At full throttle, with the proper size screwdriver, slowly start turning one of the H/S needles in segments of 1/8 turn, waiting momentarily for the engine to respond, then repeat turning. You will reach a point where the engine will start to die out. At that point, back that needle valve out approximately 1/4 turn. Now, go to the other High Speed needle valve and repeat that procedure. At some point in that 1/4 turn out, you will find the smoothest high speed setting (you can now lower the throttle rpm). That will have both high speed needle valves set correctly, and at that point you can lift that center lever adjustment of that high ridge, keeping it lifted until the point is facing the engine, then lower it into its proper position. (When you turn that lever now, you're adjusting both High Speed needle valves at the same time.)<br /><br />(Slow Speed Adjustments)<br />Now, lowering the rpms of course, take the engine out of gear and set the throttle just to where the engine will stay running. Again, in segments of 1/8 turn, slowly start turning in one of the slow speed needle valves, waiting a few seconds between each turning for the engine to respond. As you turn the s/speed needles in, the rpms will increase..... and as it does, lower the rpms to where the engine will just stay running (otherwise the rpms will climb quite high). You will reach a point whereas the engine will either start to die out or it will spit back (sounds like a mjild backfire). At that point, back the needle valve out 1/4 turn. Repeat the process with the remaining slow speed needle. Again, at some point in that 1/4 turn out, you will find the smoothest setting. When finished, tighten the jam nut somewhat, then remove and reinstall the s/speed knobs correctly (right side up).
 
Joined
Mar 20, 2003
Messages
11
Re: setting carbs on 59 evinrude

Thanks Joe,Iam trying to make this one last for one more year,before I get a new one.
 

rwise

Captain
Joined
Jul 5, 2001
Messages
3,205
Re: setting carbs on 59 evinrude

dead in water <br />1. the low speed sets at 1.5 turns out.<br />2. the high speed sets at 3/8 turn out.<br />3. the in the water adjust low speed for best idle.<br />4. then WOT, in gear, with someone you trust with your boat and your life adjust the high speed jets for best proformance.<br />5. repeat step 3 and 4 until you are happy with the responce.<br /><br />I have a 1958 50 hp this works, it may also need sync and link adjustments. If you do not have a book I can post the pages to do this on my web site for you to download. You would need winzip or something like it to uncompress the files. If you want/need it just post here or e-mail me, its in my profile.<br />Richard
 
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