no spark 1974 50 hp merc

[viperman1]

i have 74 merc 50 hp with no spark i ripped the open the distributer and there was lots of rust on the magnets i cleaned it all up now and it still wont give me spark what else can i look at that can give me this problem the switch box was also tested and it was fine. the boat did sink last fall and its the first time i tryed starting it the motor turnes over fine.

 

[12Footer]

Re: no spark 1974 50 hp merc

See if you can turn the rotor with one finger. If so, you need a new dist shaft/rotor assembly....<br />But try to find a used one on ebay, as a new one will set you back 300buks or more. I found one locally at a boneyard for 10buks, I remove..All kindsa cheaper.<br />I was tempted (before finding the 10dollar one), to JB-Weld the rotor back to the shaft.<br />Not saying this is what is wrong with yours, but it's a possablility.<br />Others are timing belt broke, stator, switchbox.rectifier,mercury tilt switch (disconnect to test), or short to ground in engine kill circuit.

 

[viperman1]

Re: no spark 1974 50 hp merc

the rotor is hard to turn the magnetes are still strong i had the switch box tested and it was good

 

[12Footer]

Re: no spark 1974 50 hp merc

Undo brown wire at switchbox and merc tilt switch lead (on same terminal)and try it.