Re: help with a 71 johnson 125 o/b she's in the water thanks
Tcamps... You state "it only starts intermidently and does not stay running when i move the selector from start to run".<br /><br />I assume that by "selector", you're speaking of the ignition switch. If so, that would indicate that you are properly applying 12v to the powerpack ONLY when the key is in the "start" position. Check the wiring and the switch itself as 12v would need to be applied to the pack on both settings.<br /><br />The carburetors..... remove, clean and rebuild them on general principles if nothing else. I'll include the adjustment provedure below.<br /><br />I'll also include the procedure for testing the powerpack on that model.<br /><br />--------------<br /><br />(Dual Carb V/4 With 4 (2 each carb) Slow Speed Adjustable N/Valves)<br /><br />The adjustment procedure of the carburetor slow speed needle valves follows. NOTE... if the needle valves turn too freely, replace the nylon bearing retainer (the nylon item at the front of the carb that the needle valve goes through first) with the newer type RED retainer #315232. If your engine has that weird linkage that connects all four of those needle valves, the newer RED retainers will enable you to discard that linkage. The RED retainers make it impossible for the needle valves to viberate out of adjustment. <br /><br />(Carburetor Adjustment - 2 Slow Speed Adjustable Needle Valves, each carburetor) <br /><br />Initial setting is: All (4) Slow speed valves = seat gently, then open 1-1/2 turns. <br /><br />Facing the carburetors, start with the top left needle valve, then the top right valve, then the bottom let valve, then the bottom right valve. It may be necessary to redo these steps to get the adjustments ideally set <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 />Do not attempt to gradually adjust all four of the valves at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve. <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 />---------------<br /><br />(Battery Capacitance Dischage Powerpack Test)<br />Various OMC Engines - 1968 to 1972)<br /><br />Purchase a small 12v bulb at your local automotive parts store (the 12v bulb is to look like a flashlight bulb, not a headlight bulb). Solder two wires to that bulb, one to the side of the bulb (ground), and the other to the positive point. <br /><br />Remove the spark plugs. With the key in the on position, make sure that you have 12v going to the pack at the terminal block (purple wire). Now, connect the ground wire from the bulb to any powerhead ground. Connect the wire from the positive point of that bulb to the powerpack wire that is connected to the coil wire on the terminal board (blue wire). <br /><br />Crank the engine and observe that bulb closely (CLOSELY!). If that bulb glows even the slightest bit, the powerpack is okay. It may be a very dim glow... just so it glows! If it doesn't glow, the pack has failed. <br /><br />Keep in mind, that type powerpack (Battery Capacitance Discharge) demands a top notch battery of at least 70 amp hours. Any less will, in time, cause powerpack failure
