Adjusting Control Rod

moganman

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Joined
Oct 5, 2003
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25
I have a 62 Johnson Seahorse 40 HP (hot water choke) that seems to run OK. I bought a carb kit and removed and cleaned the carb. I am in the process of adjustment (link and sync). The manual says on one of the final adjustments "manually rotate the armature base to its full spark position. Adjust the control rod collar to provide 1/32" clearance from the pivot pin" (clymer page 127) It seems though the engine idles much better if I adjust the collar 1/16" in the opposite direction. Is the manual giving you an ajustment starting point or is this set in stone, will it hurt anything? <br /><br />Also the manual gives the low speed needle adjustment in one chapter, "after lightly seating the needle back out 7/8 of a turn" and in he next chapter it says "back out 1 1/2 turns" :confused: (pages 127 and 171).<br />Anybody got a seloc manual or some advice would be appreciated.
 

Tinkerer2

Seaman
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Dec 19, 2003
Messages
52
Re: Adjusting Control Rod

My Clymer manual gives somewhat similar unhelpful instructions on setting the idle on my '67 V4 60 HP Evinrude. <br /><br />I followed the instructions faithfully.<br /><br />Time and time again.<br /><br />It never sounded quite right or ran quite right at idle.<br /><br />Then I just ignored the manual and went back to basics and screwed the idle screws (twin carbs) in until they seated, took them out one and half turns, and then turned each one in and out until it coughed with too little fuel on lean and slowed with too much on rich, and set it about half way between. I repeated this a few times as with twin carbs it's hard to balance them, but in the end I got a far better idle which was outside the range of idle adjustments indicated by the manual. <br /><br />Doesn't mean the manual was wrong as my carb might be worn or whatever (notwithstanding that I've replaced every wearable part in it), but I got the "right" adjustment by old methods and by ear rather than by slavishly following the manual's notion of where settings ought to be.
 

Joe Reeves

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Joined
Feb 24, 2002
Messages
13,262
Re: Adjusting Control Rod

Morgan..... Manuals can be confusing at times.<br /><br />(Synchronization Of Older 2 Cyl Engines)<br />(Such As The 28, 33, 40hp Etc models)<br /> <br />On the linkage that runs from the armature plate (the plate the coils & points set on) to the carburetor throttle roller, loosen the set screw on the brass collar that you see there and temporarily move it away from the armature plate/vertical throttle arm clevis (clevis is that thing the linkage rod slides through). We'll refer to that vertical throttle arm/armature plate clevis simply as the "clevis" from this point on.<br /> <br />Look at the cam that's attached to the front of the armature plate.... the cam that slides up against the carburetor throttle roller. You'll notice that there's a scribe mark on it. The carburetor roller should contact the cam and just start to open the throttle butterfly when that scribe mark is dead center with the roller.<br /><br />With the engine in gear (not running of course) have the armature plate advanced all the way (by hand) so that it is up against its stop. Now adjust the brass collar (set screw) on that associated linkage rod so that it is up against the clevis. It should be adjusted so that there is either no play, or just a hairs play between the collar and the clevis.<br /><br />At this point, the armature plate movement is not advancing the throttle butterfly via the rod movement, but further movement of the throttle control, although the armature plate cannot move any farther, causes the tension spring at the armature plate to allow the vertical throttle arm to move farther which now advances the carburetor throttle butterfly via the rod.<br /><br />----------<br /><br />(Carburetor Adjustment - Single S/S Adjustable Needle Valve)<br />(J. Reeves)<br /><br />Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.<br /><br />Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.<br /> <br />Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting. <br /><br />When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.<br /><br />If all else with your engine is as it should be, that should do it.<br /><br />(Edited, slightly revised 01/31/04, 4:15pm.
 

Joe Reeves

Supreme Mariner
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Feb 24, 2002
Messages
13,262
Re: Adjusting Control Rod

Tinkerer2.... The following may be of interest to you and others with the older V/4 dual downdraft carburetors.<br /><br />(Carburetor Adjustments - Older V/4 Downdraft Carb)<br />(J. Reeves)<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).
 

moganman

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Oct 5, 2003
Messages
25
Re: Adjusting Control Rod

Thank you very much. I am printing this out and doing this in the morning. :)
 
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