I have a 1984 Mercury 18xd (electric start) that I recently purchased from a coworker. The only work the previous owner did on it was a carb kit. He told me the only way he could get it to crank and run was with the trottle open.
I cleaned the carb, changed the plugs, and ran some new fuel through it. I went ahead and checked the compression. While turning it over with the starter, both cylinders were reading near 150psi.
I began to crank it over using the starter. It would fire up for a split second every now and then but die. I eventually opened the throttle near wide open and it fired and ran. After it fired up I released the throttle and it ran for approximately 15 seconds at a high rpm. I shut it off when I saw that it wasn't reving down to idle.
Since then, the started solenoid went bad (I have one ordered). So I have been using the pull chord to try to start it.
I tested the compression again using the pull chord. The top cylinder read near 140psi and the bottom read around 120psi after 5 pulls.
Now, still using the pull chord, the motor will fire up and die on the first pull. If I keep pulling the chord it will not fire again. If I give it a minute or so, and pull the chord again, it will fire and die again.
I have pulled the plugs several times after the motor fired up. The top plug is consistantly dry, and the bottom plug is consistantly wet.
I pulled the ignition coils and plug wires off of my 25xd, which runs great, and put them on the 18. Both plugs appear to be making sufficient spark on the 18.
I'm definitely not a marine technician. I have determined that, since the top spark plug is dry, and the bottom spark plug is wet after the motor fires, I am lead to beleive that the top cylinder firing and the bottom cylinder is not.
If anyone has had similar issues and found a remedy, please fill me in. Any information or comments that might help me will be greatly appreciated. Thanks in advance,
Jerid
I cleaned the carb, changed the plugs, and ran some new fuel through it. I went ahead and checked the compression. While turning it over with the starter, both cylinders were reading near 150psi.
I began to crank it over using the starter. It would fire up for a split second every now and then but die. I eventually opened the throttle near wide open and it fired and ran. After it fired up I released the throttle and it ran for approximately 15 seconds at a high rpm. I shut it off when I saw that it wasn't reving down to idle.
Since then, the started solenoid went bad (I have one ordered). So I have been using the pull chord to try to start it.
I tested the compression again using the pull chord. The top cylinder read near 140psi and the bottom read around 120psi after 5 pulls.
Now, still using the pull chord, the motor will fire up and die on the first pull. If I keep pulling the chord it will not fire again. If I give it a minute or so, and pull the chord again, it will fire and die again.
I have pulled the plugs several times after the motor fired up. The top plug is consistantly dry, and the bottom plug is consistantly wet.
I pulled the ignition coils and plug wires off of my 25xd, which runs great, and put them on the 18. Both plugs appear to be making sufficient spark on the 18.
I'm definitely not a marine technician. I have determined that, since the top spark plug is dry, and the bottom spark plug is wet after the motor fires, I am lead to beleive that the top cylinder firing and the bottom cylinder is not.
If anyone has had similar issues and found a remedy, please fill me in. Any information or comments that might help me will be greatly appreciated. Thanks in advance,
Jerid