1966 merc 650 run then stall for 25 minutes

I have a 1966 Merc 650 #2051277. A couple of years ago it developed a weird problem. I would take it out and pull a skier for about fifteen minutes and then go to pick them up and it would stall and die when I would put in idle. It would be hard to start. The carb was rebuilt and found the floats were bad. Also rebuilt the fuel pumps and then this year I took it out three times only to have it run fine while I had it at running speed for a while and then when I slowed the engine it would die and have to sit 25 minutes before it would start. Motor does not appear to be overheating. By reading other posts it sounds like trigger (don't even know where that is located) or the switchbox. Both appear to be out of production. I'm about ready to sink this thing in the middle of the lake. Help?

Re: 1966 merc 650 run then stall for 25 minutes

A 66 Mercury 650 is not CD ign. it will have a magneto, probable pts. are bad pull the mag and rebuild it

Re: 1966 merc 650 run then stall for 25 minutes

Thanks for the reply. The mechanic put in points, distributor cap and rotor when he rebuilt the carb and fuel pump. What is entailed in rebuilding the magneto?<br />Thanks,<br />mike

Re: 1966 merc 650 run then stall for 25 minutes

That should have it covered, if he cked the condenser and coil with a magneto analizer, you should disconnect the mercury switch also

Re: 1966 merc 650 run then stall for 25 minutes

Do you mean that the mercury switch should be disconnected when testing the condenser and coil? The coil was also replaced recently.

Re: 1966 merc 650 run then stall for 25 minutes

disconnect the mercury switch altogether. sometimes they get faulty and cause your ignition to kill.

Re: 1966 merc 650 run then stall for 25 minutes

just for zhits and giggles, take a timing light or spark tester with you on your next outing. when it stalls and wont restart, test with either trhe timing light or spark tester and see if its making spark during this " cool down" period. if its making spark during this down time, its definatly fuel related.<br /><br />if its NOT getting spark during this time, im betting on a merc switch. but what do i know.....

Re: 1966 merc 650 run then stall for 25 minutes

A recent camping trip had a strange event. I started the motor no problem and drove it to the camp site. A couple of hours later I went to take it out and it would not start. I checked and it had some spark but my mechanic said it was not enough to run. He found a wire to the magneto that was corroded. He replaced it and the last trip to the lake was perfect until we got to the other end of the lake and I put it in nuetral and it died. Back to the waiting for 25 miutes or so for it to start and then ran fine until I got back to the boat dock and slowed the boat to 5 mph. Of course it quit again. Will try the mercury switch. Thanks for the advice. mike