I am new to boating and just got a 1997 Searay 175 with a Mercruiser 4.3 LX. took it out 4 times and then it ran rough for a few seconds and I turned it off, checked the engine, levels, etc. and all seemed okay, but it would not start. Had to get towed off the lake which was not fun. I know I have fuel and I can see a stream of fuel in the carb when I advance the throttle, but I get no spark from the plug wires or the coil.<br />Here is what I have done: (after reading a lot of posts on this great site and talking to some freinds)<br />looked thru the wiring diagram and checked all switches.<br />Disonnected the tach - no change<br />Replaced the coil & coil wire<br />Replaced the sensor assembly in the distributor<br />Replaced the rotor and dist. cap as recommended by one of the Merc mechanics when I bought the sensor.<br />I have checked the typical things like the run switch, shift switch etc. there is a new battery with good, clean cables. Engine cranks nicely but still no spark.<br />I have 12.82 V at the battery and from + coil to block and from - coil to block I have 12.74 volts. Sorry to be so long, but I want to get all the info you guys might need to be able to help. As far as I can see the only ignition related part left is the ignition module which is a 384.00 part. I dont want to replace this unless I am sure it is bad and I dont want to throw in an expensive part if I still have some electrical condition that could cause a new module to fail.<br />Any help is appreciated.<br />Rick