72 mercury 650 spark problem

[leneve1]

my 72 650 quits with no spark. If I wait a few minutes it will start, miss and quit. I bypassed the trigger and have spark. Five years ago the same thing occurred and the dist housing with trigger and switchbox was replaced. Can a bad trigger ruin the switchbox and vise versa? Is this a problem with this particular model, as the parts are super expensive?

 

[corm]

Re: 72 mercury 650 spark problem

Hi,

One can ruin the other but it is unusual.
I would say you have a bad ing block.
I've sat on the river several times over the years
like that.

 

[leneve1]

Re: 72 mercury 650 spark problem

what is a ing block?

 

[corm]

Re: 72 mercury 650 spark problem

oops, sorry it is the switchbox.

When they start to go bad the 3 cyl one would get an open circit in them. When cooled down they would work again. I used to poor water on them and run with the hood off to get back home. We always replaced the Merc ones with the Repair ones. We had way less trouble with them on the 3 cyl engines.