I have a 1978 55 Horsepower Evinrude 55875s. Generally speaking it has been running great. The problem appears to have just surfaced out of nowhere this past weekend.
I has the manual choke on/off switch on the motor, which I had switched off. To fire it up, I would turn the key and press it inward to turn on the choke, and it would fire up, no issues. This weekend it would not start that way. It wouldn't start.
I had to remove the engine cover and flick the choke switch on to start it up, but it won't stay running at base idle, instead it has to be turned up to some 2500+ rpm to stay running. It used to idle and could even be put into gear and trolled around at about 900-1100 rpm. Now when I turn the throttle down it stalls as if it's being choked (likely because it is). It also pumps out a rich smelling exhaust. The worst part of it all, when we came to dock and shut down the motor, it started spewing a grey sludge from the exhaust and from a small hold right above the lower unit. I know this sludge to be not abnormal give that those motors are not very fuel efficient so it's excess fuel that made it through the system mixing with exhaust and water. But I know it's not supposed to look like a BP oil spill.
When I try starting it with the choke switch off, I need to use the ignition switch choke to start it which is normal, but it won't stay running unless I keep the switch pressed, or I have to rev it high to keep going.
My guess is that there must be a problem with the carb, but what specifically could it be and how can I fix it?
Further to that, how do I find parts for the carb and/or throttle linkage on the motor? Many parts are quite worn and loose.
I has the manual choke on/off switch on the motor, which I had switched off. To fire it up, I would turn the key and press it inward to turn on the choke, and it would fire up, no issues. This weekend it would not start that way. It wouldn't start.
I had to remove the engine cover and flick the choke switch on to start it up, but it won't stay running at base idle, instead it has to be turned up to some 2500+ rpm to stay running. It used to idle and could even be put into gear and trolled around at about 900-1100 rpm. Now when I turn the throttle down it stalls as if it's being choked (likely because it is). It also pumps out a rich smelling exhaust. The worst part of it all, when we came to dock and shut down the motor, it started spewing a grey sludge from the exhaust and from a small hold right above the lower unit. I know this sludge to be not abnormal give that those motors are not very fuel efficient so it's excess fuel that made it through the system mixing with exhaust and water. But I know it's not supposed to look like a BP oil spill.
When I try starting it with the choke switch off, I need to use the ignition switch choke to start it which is normal, but it won't stay running unless I keep the switch pressed, or I have to rev it high to keep going.
My guess is that there must be a problem with the carb, but what specifically could it be and how can I fix it?
Further to that, how do I find parts for the carb and/or throttle linkage on the motor? Many parts are quite worn and loose.