Re: 58 Evinrude 5.5 hp, model 5516, cooling/fuel?
UPDATE (still not fixed)...<br /><br />Well, I double-checked the coils for spark with an old plug, gapped to about 3/8" as suggested. Turns out I had a break in one plug wire, so only one cylinder was firing. Not sure how that happened, as I checked for spark once already a few weeks ago and both were sparking fine.<br /><br />Anyway, replaced the plug wire, verified spark at both plugs, and thought for SURE this would fix the problem. Went to the river... no luck. Still won't start unless throttle is cranked to max open... and even then, it only grabs for about 1-3 seconds before it dies again.<br /><br />I've been through just about every piece of this motor now. Coils are good. Plugs are good. Wires are good. Waterpump is good. Points are good and properly gapped (0.020"). Just about everything on the motor is new equipment.<br /><br />I did discover, however, that the packings inside the high and low speed needle valves somehow got chewed up, and the low-speed needle valve (the upper one, for the idle) is worn. Again, not sure how that happened... looked to be in great condition when I rebuilt the motor over the winter, but maybe it was vibrating in there or something... really don't understand it. Could this produce the problems I'm having?<br /><br />As a recap: There is definitely pressure in the system (pressure tank hisses when you unscrew the cap); definitely fuel flowing through the Quick Disconnect (fuel sprays freely if you unhook it while the tank is still pressurized); there is definitely fuel getting to the carb (the carb bowl fills up right away after a few pulls); there is definitely fuel/oil moving through the fuel line that connects the top and bottom cylinder (I have clear fuel line, so I can see it circulate at least a little when I pull the starter); there is definitely spark at both plugs now.<br /><br />Nonetheless, the motor seems starved for gas somehow. That's the only way I can make sense of why it would require full throttle to even begin to start... Is it possible that a broken reed valve or something behind the carb could be producing these symptoms? The reed valves were fine when I rebuilt the motor over the winter, but maybe they were damaged since then? (probably not... but I'm running out of ideas).<br /><br />Or could air leaks around the carb needles cause me this much trouble?<br /><br />Thanks again for all your help guys.
UPDATE (still not fixed)...<br /><br />Well, I double-checked the coils for spark with an old plug, gapped to about 3/8" as suggested. Turns out I had a break in one plug wire, so only one cylinder was firing. Not sure how that happened, as I checked for spark once already a few weeks ago and both were sparking fine.<br /><br />Anyway, replaced the plug wire, verified spark at both plugs, and thought for SURE this would fix the problem. Went to the river... no luck. Still won't start unless throttle is cranked to max open... and even then, it only grabs for about 1-3 seconds before it dies again.<br /><br />I've been through just about every piece of this motor now. Coils are good. Plugs are good. Wires are good. Waterpump is good. Points are good and properly gapped (0.020"). Just about everything on the motor is new equipment.<br /><br />I did discover, however, that the packings inside the high and low speed needle valves somehow got chewed up, and the low-speed needle valve (the upper one, for the idle) is worn. Again, not sure how that happened... looked to be in great condition when I rebuilt the motor over the winter, but maybe it was vibrating in there or something... really don't understand it. Could this produce the problems I'm having?<br /><br />As a recap: There is definitely pressure in the system (pressure tank hisses when you unscrew the cap); definitely fuel flowing through the Quick Disconnect (fuel sprays freely if you unhook it while the tank is still pressurized); there is definitely fuel getting to the carb (the carb bowl fills up right away after a few pulls); there is definitely fuel/oil moving through the fuel line that connects the top and bottom cylinder (I have clear fuel line, so I can see it circulate at least a little when I pull the starter); there is definitely spark at both plugs now.<br /><br />Nonetheless, the motor seems starved for gas somehow. That's the only way I can make sense of why it would require full throttle to even begin to start... Is it possible that a broken reed valve or something behind the carb could be producing these symptoms? The reed valves were fine when I rebuilt the motor over the winter, but maybe they were damaged since then? (probably not... but I'm running out of ideas).<br /><br />Or could air leaks around the carb needles cause me this much trouble?<br /><br />Thanks again for all your help guys.
