1959 Mercury Mark 58A - ignition problem...

bigdawg

Recruit
Joined
Jul 29, 2002
Messages
3
My nephew bought a Mercury Mark 58a about a year and half ago. He has been running it every weekend since with no problems. It's mounted on a 14 ft runabout. (He lives on the water and really enjoys his boat)<br /><br />Lately, he has been having a problem with ignition and has been unable to use the boat. The motor will not idle and a timing light indicates no spark in the bottom 2 cylinders. It may have spark in these 2 at higher RPM. Tried changing the condenser but no luck. He does really have the money to guess at the distributor cap. ($82) Any ideas would be appreciated. <br /><br />THANKS,<br /><br />BigDawg<br />Wisconsin
 

corm

Lieutenant Junior Grade
Joined
May 12, 2000
Messages
1,241
Re: 1959 Mercury Mark 58A - ignition problem...

Hi,<br />You could check to see that the cam is not wore down for the points. Set pts at .010. take out the set screw that holds in the plug wire and cut the wire where the set screw makes contact with it and reinstall the wire and set screw. Sometimes the wire burns away inside the cap. Unless the cap is ceacked bad it should work ok. Clean it with break clean or the equilvilant.<br />You can spin the shaft by hand to see if you have spark with out putting the dis back on the motor, saves some time.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: 1959 Mercury Mark 58A - ignition problem...

Check that the pegs in the distributor, which are a high-copper metal, are not corroded. They will often pick up a greenish fuzz after awhile. You can clean them up with 220/320 sand paper. Also, clean up the in and out on the rotor itself. Make sure the center graphite pick-up is in place and in good shape. Check the plug wires for cracks.<br />- Scott
 
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