So this has been a long and frustrating summer. In march I purchased a 1991 Chris Craft Concept 187 with a 5.0 Ford OMC cobra. The boat had not been winterized properly and the block had cracked. I bought a remanufactured long block and replaced the motor and rebuilt the carb. The motor started and ran great. During the first lake test the boat would die when I tried to put it in gear. I had to disconnect the micro switches and then it would shift into gear fine.
After being on the water for about 15 minutes of running perfectly, the boat developed a terrible miss. It was not dependent on rpm and would hiss and sputter but did not die. It started very suddenly and never got any better. Well I started to fix the miss by draining the gas and replacing it with fresh 100% gas( old gas was not bad, it ran through my lawn mower fine). I then replaced the coil after I noticed it would get very hot with the ignition on but the motor not running. Neither of these changes affected the miss.
So after my initial ideas failed I checked for an intake leak with break fluid(there is not one), replaced the spark plug wires, replaced the rotor cap and button and replaced the ignition module. I also pulled off the valve covers to make sure no rocker arms had gotten lose and check the valve movement(it appeared normal). During this I discovered that I appear to have a weak spark. I did the primary voltage test in the SELOC manual and my voltage at the coil is wrong.
When I attach the negative lead to the negative battery post and the positive lead to the positive post I only get eight volts instead of 12-13 volts( with the battery at 12.3 volts). The manual says if it is less than the recommended voltage to do a voltage drop test. Well my voltage drop test results were normal. When I check the negative side of the coil I get less than two volts, which is why I tried replacing the coil and ignition module. I have also tried disconnecting the ESA with no change.
I've tried pulling plug wires to try to see if its just a certain cylinder that is missing but it seems like its the whole motor not just a single cylinder. The motor starts right up every time I just can't figure out whats causing my ignition issues. Any ideas you guys have would be greatly appreciated, I am lost at this point.
After being on the water for about 15 minutes of running perfectly, the boat developed a terrible miss. It was not dependent on rpm and would hiss and sputter but did not die. It started very suddenly and never got any better. Well I started to fix the miss by draining the gas and replacing it with fresh 100% gas( old gas was not bad, it ran through my lawn mower fine). I then replaced the coil after I noticed it would get very hot with the ignition on but the motor not running. Neither of these changes affected the miss.
So after my initial ideas failed I checked for an intake leak with break fluid(there is not one), replaced the spark plug wires, replaced the rotor cap and button and replaced the ignition module. I also pulled off the valve covers to make sure no rocker arms had gotten lose and check the valve movement(it appeared normal). During this I discovered that I appear to have a weak spark. I did the primary voltage test in the SELOC manual and my voltage at the coil is wrong.
When I attach the negative lead to the negative battery post and the positive lead to the positive post I only get eight volts instead of 12-13 volts( with the battery at 12.3 volts). The manual says if it is less than the recommended voltage to do a voltage drop test. Well my voltage drop test results were normal. When I check the negative side of the coil I get less than two volts, which is why I tried replacing the coil and ignition module. I have also tried disconnecting the ESA with no change.
I've tried pulling plug wires to try to see if its just a certain cylinder that is missing but it seems like its the whole motor not just a single cylinder. The motor starts right up every time I just can't figure out whats causing my ignition issues. Any ideas you guys have would be greatly appreciated, I am lost at this point.
