1987 Mercruiser 4.3L / 185hp / Alpha One.
I recently ran into a new problem that seems to be ignition related but I'm not positive.
I was lake testing the boat after replacing the impeller for a previous overheating problem. After running the boat for about an hour (about 30 min in no wake zone and 30 min between 1/2 and 3/4 throttle. I put the kids on a tube for a fun afternoon. The boat started up immediately and as I passed the 1/4 throttle point, the motor began to spit, sputter and stalled. I raised the lid to see if the carb may have flooded, but I did not see or smell any signs of flooding. I had to hit the starter 2 different times, about 5 sec each time before it started back up, but once it did, it seemed to idle fine. Typically, the boat starts almost immediately when you hit the starter.
The motor went into gear just fine and just like before, anything above idle, the motor would spit and sputter until it stalled. This scenerio was repeated 5 - 6 times before I gave up and idled back in and trailered it home.
At home, I replaced the distributor cap, plugs and plug wires (none of which looked bad and was all replaced last summer).
Round 2 - Took her back to the lake next day and thought the issue was solved, but after about an 1 1/2 hour the problem came back. Brought back to the house and pulled the Fuel/Water seperator filter off and dumped the contents into a glass jar to determine if is a possible fuel problem. The gas from the filter apeared to be clean, no water / trash visible.
Anyone have any other suggestions? It does have the Thunderbolt IV ignition system. I thought about replacing the coil but I'm not sure if this is a sympton of a bad coil. I though when a coil goes, it's gone for good. Any suggestions will be greatly appreciated.
I recently ran into a new problem that seems to be ignition related but I'm not positive.
I was lake testing the boat after replacing the impeller for a previous overheating problem. After running the boat for about an hour (about 30 min in no wake zone and 30 min between 1/2 and 3/4 throttle. I put the kids on a tube for a fun afternoon. The boat started up immediately and as I passed the 1/4 throttle point, the motor began to spit, sputter and stalled. I raised the lid to see if the carb may have flooded, but I did not see or smell any signs of flooding. I had to hit the starter 2 different times, about 5 sec each time before it started back up, but once it did, it seemed to idle fine. Typically, the boat starts almost immediately when you hit the starter.
The motor went into gear just fine and just like before, anything above idle, the motor would spit and sputter until it stalled. This scenerio was repeated 5 - 6 times before I gave up and idled back in and trailered it home.
At home, I replaced the distributor cap, plugs and plug wires (none of which looked bad and was all replaced last summer).
Round 2 - Took her back to the lake next day and thought the issue was solved, but after about an 1 1/2 hour the problem came back. Brought back to the house and pulled the Fuel/Water seperator filter off and dumped the contents into a glass jar to determine if is a possible fuel problem. The gas from the filter apeared to be clean, no water / trash visible.
Anyone have any other suggestions? It does have the Thunderbolt IV ignition system. I thought about replacing the coil but I'm not sure if this is a sympton of a bad coil. I though when a coil goes, it's gone for good. Any suggestions will be greatly appreciated.