Re: 1966 JOHNSON 3 HP WON'T REV UP
DRJ,<br />I'm going with both DJ and Paul on this one. Replace the float. The old cork float is going to be a problem at some time, so change it now and save your sanity.<br /><br />As for the Boss gasket. It vital for the proper mixture setting to work properly. When you replace the boss gasket, you'll find that the upper and lower carb body won't come together completely. Both carb halves are being held apart slightly by the new gasket. Replacing the carb body screws will pull both halves together, compressing the boss gasket, and effecting a good seal. When the boss gasket leaks, engine intake vacume pulls fuel directly from the lower carb bowl and not thru the main metering jet causing an over rich mixture.<br />---------------------------------------------<br />Carb Adjustment per Joe Reeves (Thanks Joe..again)
<br /><br />(Carburetor Adjustment - Single S/S Adjustable Needle Valve)<br /><br />Initial setting is: Slow speed = seat gently, then open 1-1/2 turns. (All carbs at the<br />same time)<br /><br />(On the following adjustment, finish one carb before going on to the next one, then<br />double check the adjustments).<br /><br />Start engine and set the rpms to where it just stays running. In segments of 1/8<br />turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to<br />respond. As you turn the valve in, the rpms will increase. Lower the rpms again to<br />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<br />(sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4<br />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<br />them again unless the carburetor fouls/gums up from sitting, in which case you<br />would be required to remove, clean, and rebuild the carburetor anyway.
