2000 Mercury 200efi random no spark

[Xlanci]

Hey guys I just recently bought this new boat with a Mercury 200efi on it and I’ve test driven it over 18 miles no problems at all but then I go to take it out again and it starts and gets off the trailer but when I docked it and tried to start again nothing it would just sit there and crank so I got home tested spark and have no spark and noticed both the power wires going to the cdm are at 12.2v until it starts cranking then it drops down to 10v so I tried adding power with a power probe and that seemed to be effective but now after cleaning everything up I go to run it and it’ll start very inconsistently sometimes it’ll start after priming for a bit or something not at all so if anyone else has delt with this before or knows of solution I haven’t thought of that would be very appreciate it thanks in advance

 

[workboot]

I have the same motor but a 2002, not sure about your spark problem but I never have to pump the primer bulb all season it stays firm all the time, maybe you have a bad fuel pump , there are 2. one diaphragm and one electric. there's a Shrader valve (looks like a car tire air valve) on top front of motor. Get a fuel gauge (auto parts stores loan them out free) hook to Shrader valve, then turn key to on position without starting, gauge should go to 41 to 45 psi and stay there, then crank motor and might drop a little and if it starts should stay at 41 to 45 psi, mine ended up needing the electric pump. But first try a known good remote fuel tank to eliminate any hose or air leaks. Also get yourself a real mercury service manual, I got one off ebay for $35.00 5 years ago, there are so many test you can perform so you are not throwing money on parts that you don't need. I bought the boat and motor 5 years ago and that pump when bad the first year, but since then it's been great, good luck and keep us up to date on your progress