I took it down to the water today and while it was on the trailer I started the engine checked the dwell. Once the engine was running, the dwell was 24, so I made the adjustments and set the dwell at 31. I reset the timing to 6* BTDC. The engine actually ran much much much better while it was on the trailer in the water after that.
I was setting the idle screw and I noticed something strange. I would set the idle at 700 RPM, and then I would let the engine run for a bit to make sure it would not over heat or anything. As it sat there, the idle would all the sudden slowly started increasing from 700, up to like 1300 RPM without me touching anything. Then I adjusted the idle screw and brought it back to 700, then a minute later the idle would go down to around 400, I adjusted it again to 700, and then a few minutes later it slowly went up to 1200 RPM again. As I was adjusting the idle mixture screw, I noticed that it would run slightly different when I closed the mixture screw 100%, but the engine did still run, so I am thinking there is a vacuum leak. Is the idle up and down issue a symptom of a vacuum leak as well? I will take some body cleaner and spray it around the base and manifold to see if I can locate it, but I just wanted to see if these idle symptoms are due to a vacuum leak as well?
When I got the boat home, I did realize that I did not retorque the exhaust manifold after the first startup as the manual said, so I did that and the 2 bolts that hold the shift plate on had about 1/2-1 full turn to reset them to 23 ft #, so maybe that is the cause of the air leak?
I replaced the head gasket and manifold gasket and I took the carb apart cleaning every part and it was actually pretty clean. There were no parts of the carb that looked concerning. Set the float to spec and installed new gaskets. Besides the idle not staying at 700 it runs great.
I was setting the idle screw and I noticed something strange. I would set the idle at 700 RPM, and then I would let the engine run for a bit to make sure it would not over heat or anything. As it sat there, the idle would all the sudden slowly started increasing from 700, up to like 1300 RPM without me touching anything. Then I adjusted the idle screw and brought it back to 700, then a minute later the idle would go down to around 400, I adjusted it again to 700, and then a few minutes later it slowly went up to 1200 RPM again. As I was adjusting the idle mixture screw, I noticed that it would run slightly different when I closed the mixture screw 100%, but the engine did still run, so I am thinking there is a vacuum leak. Is the idle up and down issue a symptom of a vacuum leak as well? I will take some body cleaner and spray it around the base and manifold to see if I can locate it, but I just wanted to see if these idle symptoms are due to a vacuum leak as well?
When I got the boat home, I did realize that I did not retorque the exhaust manifold after the first startup as the manual said, so I did that and the 2 bolts that hold the shift plate on had about 1/2-1 full turn to reset them to 23 ft #, so maybe that is the cause of the air leak?
I replaced the head gasket and manifold gasket and I took the carb apart cleaning every part and it was actually pretty clean. There were no parts of the carb that looked concerning. Set the float to spec and installed new gaskets. Besides the idle not staying at 700 it runs great.
