How to check spark

[Mirko]

I'm a real dummy when it comes to outboards and other motors, for that matter. I often see a recommendation to check the spark or spark plugs to troubleshoot some conditions. I read that there should be a spark of appx 1/4" and it should be fairly bright.<br /><br />My question is: How do you do this? Spark between what and what? How do you make the possible spark happen. I assume that you take out one spark plug holder and hold it close to something else. Do you remove all the holders or just that one spark? Do you let the engine start with only 3 plugs connected? Will it? I remember being shocked by a lawnmower when I was a kid and it surprised the hell out of me. Didn't know there was electricity there!<br /><br />Please elaborate on this spark test as it seems to be the starting point of so much that is discussed in this forum.<br /><br />Yes I have a factory manual, and a Seloc Manual and a factory parts catalog on order. I'm just a little slow, is all.<br /><br />'94 115hp Johnson.<br /><br />Thanks in advance,<br /><br />Mirko

 

[G DANE]

Re: How to check spark

Hi Mirko<br /><br />The best way is to have some kind of sparktester to attach all plugwires to. The other side of the sparktester is connected to ground. On this, it is possible to adjust gap to jump for all 4 sparks to i.exa 5/16" Its a good way to compare the sparks and see if one is weak. I lack of this, do following: Unscrew all 4 sparkplugs to avoid starting the motor. Place the three you´r not testing with threads to a good ground ( motor block or bolt ) Put a nail or screw in the 4th sparkplug lead, hold it with a clean dry cloth or insulated plier. Hold the nail 5/15" from a bolt in motorblock, make someone cranck the motor and watch spark jump. Repeat procedure with the other 3. Just make sure, when observing 1 that the three others have ground connection, so they can spark in the plug. If no spark can jump, a lot of current builds up in power pack, and if you have bad luck, it will burn through to ground somewhere internally in powerpack - the black box.<br />Sorry for being longwinded, but trying to explain the basics.

 

[bubbakat]

Re: How to check spark

mirko see if this will help yea web page

 

[OBJ]

Re: How to check spark

Thanks for the web page bubba....that gave me an idea.....it hurt my head to.