1973? 500 50 hp mecrury outboard

[butcher_boy]

engine specs: <br />4cyln<br />thunderbolt ignition with energizer pointless. <br /><br />problem: no spark. <br /><br />I bought this boat a few days ago. it was running fine but he solenoid was bad so i would "hot wire it" wich was fine. i got new solenoid then i burned my starter. no problem i could easily start it via pull rope. as i was out on the lake going in reverse and water shooting over the back ( ) i put it in reverse and it died. and ever since then i was unable to start it. <br />i did hear some "arcing noises by the bilge pump" and now i have no spark at all from the plugs. <br /><br />i had the starter rebuilt and still no spark. does anybody know of a way to test the switch box? or test the distributur? i am hoping (cash wise) that its the distributor rather then the switch box. any help would be great. this is my first boat and i am making lots of mistakes. like not letting air into the gas can :"> . <br /><br />help!

 

[butcher_boy]

Re: 1973? 500 50 hp mecrury outboard

serial number is 3718495

 

[aeronutt29]

Re: 1973? 500 50 hp mecrury outboard

You are about to learn WAY more than you ever expected about the working of that motor. The switchbox is VERY sensitive to stray current and especially to reversed current. I fried one by cranking my motor with the spark plugs removed. If the spark doesn't have a plug to jump into, it seems to send some sort of high voltage feedback up the wire and into the switchbox. Fried mine in about 2 seconds. I heard some snapping sounds from the wires for 2 seconds and then nothing. By then it was too late. The other really fast way to fry the box is by connecting the battery backwards. You don't even need to try starting the motor to fry the switchbox using this trick!<br /><br />Unfortunately, there is no way that an average backyard mechanic can fully test the switchbox. You can do a test that indicates "could be good" or "is definately bad" by testing the voltage at the brown wire on the 4-wire side while the starter is cranking. You should get about 2.5 volts. If you get no volts, you definately have a bad switchbox. If you get 2.5 volts, then it's POSSIBLE that the switchbox is good. To properly test it requires a "peak voltage" reading from a meter that costs as much as the new switchbox. The solution I used instead of buying the new $350 OEM switchbox was to buy an aftermarket unit made by Rapair for $200. Go to http://www.seilermarine.com to order one. The Rapair unit comes with a year warranty too so you don't have to worry about blowing another switchbox. The down side to that unit is that there is no provision for a tachometer connection so your tach won't work.