Hi everyone,
A friend and I have been working on a mercruiser 470 we bought last summer. We've had the starter rebuilt, the carb rebuilt, changed the spark plugs, cap, rotor (already had electronic ignition), and replaced the starter solenoid with a generic ford-style solenoid. We set the timing to 4 deg BTDC and are getting fuel and spark (the engine will "speed up" as if it's going to start upon initially turning the key but has never "actually" started). I downloaded the service manual while the link was still alive and have gotten myself very confused about the ignition wiring. First of all, we have the prestolite starter which does not have an attached solenoid. So, it seems that we should have bought a "switch type" solenoid (see attached images from the service manual) which gives 12 volts to the coil during the momentary start when the key is in the start position- is this correct? If that is the case, is there anything theoretically wrong with simply attaching this purple-yellow wire to the large post on the solenoid that sends 12 volts to the starter motor when the key is in the start position? Also, could someone please explain to me how the coil receives power when the key is in the run position (I don't understand the "resistance wire" which from the diagram seems to come from the carb)? The person who had the boat before us really tore apart the electrical system and we have been having a hard time piecing everything back together. Thanks- and results of a compression test should be posted tomorrow! Also- any other advice as to why our engine isn't starting would be greatly appreciated!
Jerry
A friend and I have been working on a mercruiser 470 we bought last summer. We've had the starter rebuilt, the carb rebuilt, changed the spark plugs, cap, rotor (already had electronic ignition), and replaced the starter solenoid with a generic ford-style solenoid. We set the timing to 4 deg BTDC and are getting fuel and spark (the engine will "speed up" as if it's going to start upon initially turning the key but has never "actually" started). I downloaded the service manual while the link was still alive and have gotten myself very confused about the ignition wiring. First of all, we have the prestolite starter which does not have an attached solenoid. So, it seems that we should have bought a "switch type" solenoid (see attached images from the service manual) which gives 12 volts to the coil during the momentary start when the key is in the start position- is this correct? If that is the case, is there anything theoretically wrong with simply attaching this purple-yellow wire to the large post on the solenoid that sends 12 volts to the starter motor when the key is in the start position? Also, could someone please explain to me how the coil receives power when the key is in the run position (I don't understand the "resistance wire" which from the diagram seems to come from the carb)? The person who had the boat before us really tore apart the electrical system and we have been having a hard time piecing everything back together. Thanks- and results of a compression test should be posted tomorrow! Also- any other advice as to why our engine isn't starting would be greatly appreciated!
Jerry
