I've got a 2005, 40hp, 2 stroke, 3 cylinder, oil injected, mercury outboard. I have tried just about everything I can possibly think of, and still can't figure out what is wrong with it. If anyone has any clues I havent tried it would be greatly appreciated.
Here is the full story:
I got this boat (2005 16' starcraft 180 dlx) last summer after it had been sitting in a driveway for about 2 years, cleaned it up, everything looked great besides the carpet. Outboard was spotless under the cowling, brand new trailer, looks like it had very few hours on the water in general. Only thing slightly worrying was a very chewed prop in one of the cabinets, but there was a brand new one on the outboard itself. We tried getting it running and after a bit, finally got the cylinders firing, but it would not run for very long at all. Took it to a mechanic and had the carburetors cleaned, then took it out on the water. Ran it for about 25 minutes full throttle with no issue. We stopped it and left it idling for a few minutes before it died. Primed the bulb and it started back up, didnt think much of it. After that we had it shrink wrapped and properly winterized, as we planned on doing a full renovation this spring.
Fast forward to this spring, sold my old boat, got new carpet in the starcraft, brand new starting battery, and cleaned everything top to bottom. Then we turn it over and it fires right up like a dream, after about 3 minutes it dies though. This continued to happen before we believed it had a fuel delivery issue, since the carbs had just been cleaned in the fall. This continued to happen, so I took apart just about every aspect of the fuel delivery system.
So far I have:
-put new diaphragms and gaskets in the fuel pump, triple checked everything was correctly reassembled
-checked all the lines for blockages, even bought new lines and primer bulb
-tested the fuel tank pickup, cleaned everything I could on it
-whacked the cylinders to check for stuck carb floats
-checked the fuel filter for buildup
Today we checked the compression of the cylinders and I found the results to be odd. We used a snap on compression checker and all three cylinders were almost exactly 75lbs, normally these outboards are suppose to run 120-130 as far as I have read. The thing I thought was odd was that all the cylinders were so low and similar in compression, yet when the carbs were primed with fuel it ran great until the fuel ran out. Going to get a different compression checker tomorrow to verify that these number are correct.
So right now here are the symptons/issues I have indentified:
-after priming the bulb and getting fuel into the carbs, it will start up and run fine for just about 3 minutes everytime before all the fuel in the line is emptied and the outboard stalls
-when running the starter, you can feel the air pressure in the fuel pump air lines, and the ingoing/outgoing fuel line connections in the fuel pump, although in my opinion it feels faint and weak
-you cannot however, feel the suction at the bottom of the fuel line where the hose meets the fuel tank
-spark plugs were a bit gunked up, but who knows the last time they were changed
I might be missing somethings I tried, but like I said I have spent countless hours now trying to figure this out. I read it might also be a blown head gasket, but I just graduated college and dont have the money to rebuild the engine if its compression is ruined or the head gasket is blown.
Thanks in advance if you made it all the way through this post and if you have any advice for me.
Here is the full story:
I got this boat (2005 16' starcraft 180 dlx) last summer after it had been sitting in a driveway for about 2 years, cleaned it up, everything looked great besides the carpet. Outboard was spotless under the cowling, brand new trailer, looks like it had very few hours on the water in general. Only thing slightly worrying was a very chewed prop in one of the cabinets, but there was a brand new one on the outboard itself. We tried getting it running and after a bit, finally got the cylinders firing, but it would not run for very long at all. Took it to a mechanic and had the carburetors cleaned, then took it out on the water. Ran it for about 25 minutes full throttle with no issue. We stopped it and left it idling for a few minutes before it died. Primed the bulb and it started back up, didnt think much of it. After that we had it shrink wrapped and properly winterized, as we planned on doing a full renovation this spring.
Fast forward to this spring, sold my old boat, got new carpet in the starcraft, brand new starting battery, and cleaned everything top to bottom. Then we turn it over and it fires right up like a dream, after about 3 minutes it dies though. This continued to happen before we believed it had a fuel delivery issue, since the carbs had just been cleaned in the fall. This continued to happen, so I took apart just about every aspect of the fuel delivery system.
So far I have:
-put new diaphragms and gaskets in the fuel pump, triple checked everything was correctly reassembled
-checked all the lines for blockages, even bought new lines and primer bulb
-tested the fuel tank pickup, cleaned everything I could on it
-whacked the cylinders to check for stuck carb floats
-checked the fuel filter for buildup
Today we checked the compression of the cylinders and I found the results to be odd. We used a snap on compression checker and all three cylinders were almost exactly 75lbs, normally these outboards are suppose to run 120-130 as far as I have read. The thing I thought was odd was that all the cylinders were so low and similar in compression, yet when the carbs were primed with fuel it ran great until the fuel ran out. Going to get a different compression checker tomorrow to verify that these number are correct.
So right now here are the symptons/issues I have indentified:
-after priming the bulb and getting fuel into the carbs, it will start up and run fine for just about 3 minutes everytime before all the fuel in the line is emptied and the outboard stalls
-when running the starter, you can feel the air pressure in the fuel pump air lines, and the ingoing/outgoing fuel line connections in the fuel pump, although in my opinion it feels faint and weak
-you cannot however, feel the suction at the bottom of the fuel line where the hose meets the fuel tank
-spark plugs were a bit gunked up, but who knows the last time they were changed
I might be missing somethings I tried, but like I said I have spent countless hours now trying to figure this out. I read it might also be a blown head gasket, but I just graduated college and dont have the money to rebuild the engine if its compression is ruined or the head gasket is blown.
Thanks in advance if you made it all the way through this post and if you have any advice for me.