Hello all. I will start first with a scenario then follow up with my questions.
My cousin purchased a boat a few weeks ago. Its a 94 Caravelle Legend 2100. the engine was replaced by a previous owner. The new replacement is a 95 Merc 5.0 LX (305). The person he bought it from had purchased the boat in the US, and brought it into Canada last summer. He never actually registered the boat in Canada though, and sold it to my cousin a few weeks ago. So I would assume it has been sitting in storage for the past year at least. The motor was supposedly rebuilt before it was installed, and it has about 100 hours on the boat since the installation. Now, the existence of this thread obviously indicates there may be something going on.
So, yesterday was the maiden voyage for the boat. the boat started fine, but then sputtered out and died almost instantly. We had to give it a fair amount of throttle to get it to start, and then to keep it running it was at about 1/2 throttle. after it warmed up we were able to put the throttle back down to let it idle. But within a matter of seconds it started sputtering and then would eventually die if we did not open it up again.
With the prop out of the water still we had TONS of black smoke coming out of the back and a VERY strong smell of unburnt fuel. It would seem obvious that there is either an over fueling problem, a lack of spark, or a lack of air.
We did take the boat out for a run anyway (stupid us!) and the boat would NOT go over 3000 rpm. We could coax it up to 3000 rpm, but when you opened it up past that you could feel the power fall off and the engine would start sputtering. If you didnt start opening and closing the throttle it would have actually died, but we could save it by going full closed and part open until the fuel would burn out and let it run again.
So, we went back to the dock, pulled the boat out of the water and now its sitting in my driveway.
So, We pulled the plugs, I was not surprised to see them completly BLACK!. BUT, the question now is......
Are they black BECAUSE the carb is dumping in too much fuel, so they got all carboned up?
Or
Are the plugs bad, and so the engine started running rich, and now the plugs are black?
We are getting some new plugs tomorrow and going to put those in, but I am pretty sure that there is going to need to be some adjustment done to the carb as well. The problem is I cant find really any information on adjusting the carb. What I did find was "adjust the carb". Which is great, if I knew where to look. I am not dumb when it comes to engines, but have NEVER been around a boat before. I also have not worked on ANYTHING with a carb since about 91 or 92, so its been a few years. If anyone has a manual scan that shows the procedure or can point me to a thread that talks about the steps it would be handy.
Also, when we do the plugs I wanted to verify the timing on it. May as well make sure everything else is good while we have the thing a part.
If anyone has any suggestions, or ideas based on what I posted above it would be appreciated.
Oh, I also noticed while we were running it in the driveway that the point that it starts to sputter out is where the little arm pushes down a shaft that squirts a spray of fuel into the carb. I imagine that is there on purpose, but because the engine is running so rich already that is what floods it out. I didnt want to start messing with anything until the plugs are done. Maybe that will cure the whole thing. But just in case it would be nice if I can already know where to go after that.
Thanks in advance.
My cousin purchased a boat a few weeks ago. Its a 94 Caravelle Legend 2100. the engine was replaced by a previous owner. The new replacement is a 95 Merc 5.0 LX (305). The person he bought it from had purchased the boat in the US, and brought it into Canada last summer. He never actually registered the boat in Canada though, and sold it to my cousin a few weeks ago. So I would assume it has been sitting in storage for the past year at least. The motor was supposedly rebuilt before it was installed, and it has about 100 hours on the boat since the installation. Now, the existence of this thread obviously indicates there may be something going on.
So, yesterday was the maiden voyage for the boat. the boat started fine, but then sputtered out and died almost instantly. We had to give it a fair amount of throttle to get it to start, and then to keep it running it was at about 1/2 throttle. after it warmed up we were able to put the throttle back down to let it idle. But within a matter of seconds it started sputtering and then would eventually die if we did not open it up again.
With the prop out of the water still we had TONS of black smoke coming out of the back and a VERY strong smell of unburnt fuel. It would seem obvious that there is either an over fueling problem, a lack of spark, or a lack of air.
We did take the boat out for a run anyway (stupid us!) and the boat would NOT go over 3000 rpm. We could coax it up to 3000 rpm, but when you opened it up past that you could feel the power fall off and the engine would start sputtering. If you didnt start opening and closing the throttle it would have actually died, but we could save it by going full closed and part open until the fuel would burn out and let it run again.
So, we went back to the dock, pulled the boat out of the water and now its sitting in my driveway.
So, We pulled the plugs, I was not surprised to see them completly BLACK!. BUT, the question now is......
Are they black BECAUSE the carb is dumping in too much fuel, so they got all carboned up?
Or
Are the plugs bad, and so the engine started running rich, and now the plugs are black?
We are getting some new plugs tomorrow and going to put those in, but I am pretty sure that there is going to need to be some adjustment done to the carb as well. The problem is I cant find really any information on adjusting the carb. What I did find was "adjust the carb". Which is great, if I knew where to look. I am not dumb when it comes to engines, but have NEVER been around a boat before. I also have not worked on ANYTHING with a carb since about 91 or 92, so its been a few years. If anyone has a manual scan that shows the procedure or can point me to a thread that talks about the steps it would be handy.
Also, when we do the plugs I wanted to verify the timing on it. May as well make sure everything else is good while we have the thing a part.
If anyone has any suggestions, or ideas based on what I posted above it would be appreciated.
Oh, I also noticed while we were running it in the driveway that the point that it starts to sputter out is where the little arm pushes down a shaft that squirts a spray of fuel into the carb. I imagine that is there on purpose, but because the engine is running so rich already that is what floods it out. I didnt want to start messing with anything until the plugs are done. Maybe that will cure the whole thing. But just in case it would be nice if I can already know where to go after that.
Thanks in advance.