I Have a 1987 Mercruiser 200HP blackmax. I am having some difficulty getting it running right and looking for some help. I got on the water fired it up and everything was great, ran smooth, idled great and had good throttle response. Cruising it out to the sand bar the alarm came on, so I shut it down. Started it back up idled good for about 10 seconds then the alarm came on. I check to make sure that I had oil coming out the exhaust, and everything was good. Fired it back up and cruised it for a second with the alarm on and when the motor hit 2100 rpms the alarm went off, but there was no change in performance.
It did bog down on me on my way out, let out of the throttle got back into it and it didn't bog. Shut it off at the sand bar for about 8 hours. Started it up to leave idled great with no alarm. Then it shut off by itself and I had to get towed back. Brings us to this morning when I cleaned the fuel pump, and a new fuel line to the top carb. That stopped the air in the fuel problem. Still had an alarm at idle but not at 2100 rpm. Checked all the fuses and power to the coils, stator, recitifier and inner switch box, they were ok.
On this motor theres a block on the right side of the motor where the brown wire out of the inner box switch, coolant temp sensor and what I believe is the alarm sensor(brown wire which heads into the boat up front has 12volts key on). When I seperate them the boat still idles fine and now has no alarm. Now if I jump the brown wire (that comes from the front of the boat), and the brown wire from the inner box switch, the alarm kicks on but the motor doesn't change. Maybe a fault in the inner box switch?
I put it on the water today and now it won't rev up under load and just falls on it's face, like it's choking itself out. Compression is good on the motor. Could it be in the carbs? Possibly a main jet sticking? The right cylinder head temp is about 40* hotter than the left which is at 86*. It idles fine but tip into the gas a little bit and it stalls, definatly not firing on all 6. Oh it has brand new plugs in it too (All have great spark).
Im stuped for right now. Sound I be looking for an electrical issue, or a fuel issue. Thanks for any help!
It did bog down on me on my way out, let out of the throttle got back into it and it didn't bog. Shut it off at the sand bar for about 8 hours. Started it up to leave idled great with no alarm. Then it shut off by itself and I had to get towed back. Brings us to this morning when I cleaned the fuel pump, and a new fuel line to the top carb. That stopped the air in the fuel problem. Still had an alarm at idle but not at 2100 rpm. Checked all the fuses and power to the coils, stator, recitifier and inner switch box, they were ok.
On this motor theres a block on the right side of the motor where the brown wire out of the inner box switch, coolant temp sensor and what I believe is the alarm sensor(brown wire which heads into the boat up front has 12volts key on). When I seperate them the boat still idles fine and now has no alarm. Now if I jump the brown wire (that comes from the front of the boat), and the brown wire from the inner box switch, the alarm kicks on but the motor doesn't change. Maybe a fault in the inner box switch?
I put it on the water today and now it won't rev up under load and just falls on it's face, like it's choking itself out. Compression is good on the motor. Could it be in the carbs? Possibly a main jet sticking? The right cylinder head temp is about 40* hotter than the left which is at 86*. It idles fine but tip into the gas a little bit and it stalls, definatly not firing on all 6. Oh it has brand new plugs in it too (All have great spark).
Im stuped for right now. Sound I be looking for an electrical issue, or a fuel issue. Thanks for any help!
