spark tester?

[brdm]

I am having some problems with a 1998 200 HP Johnson Oceanrunner that I think are related to one or more cylinders not firing. Can someone please give me some advise on making a spark tester so that I can check the spark on each of the cylinders. Thanks.

 

[tashasdaddy]

Re: spark tester?

the good Joe Reeves will tell you how to make a home made one with some wire, nails, and a board, and it's adjustable.

http://forums.iboats.com/showthread.php?t=205652&highlight=spark+tester

 

[BoatBuoy]

Re: spark tester?

Here's one I made:

 

[Mike722]

Re: spark tester?

One thing to remember is that with a spark plug under compression, it is harder to jump the gap. Open air testers require a larger gap for a true test.

 

[brdm]

Re: spark tester?

Thanks for the ideas. I am going to put one together and see if I can find out the reason for a rough running engine.

 

[HighTrim]

Re: spark tester?

you can also buy one with increments on it and everything for a few bucks, not expensive at all

 

[brdm]

Re: spark tester?

From the one pictured: I assume the red wire with alligator clip end goes to ground somewhere on the powerhead and you are connecting the spark plug wire to the threaded screws somehow?

Hightrim, any idea where I can purchase one in the future. I have looked around at a few of the marine shops around and have not been able to find one.
Thanks everyone.

 

[Mickyfinn]

Re: spark tester?

Brdm- I made one like Joe Reeves, and did a pretty good job of it, but when using it I was thinking I had weak spark on two cyls. I later found one at Advanced Auto parts that was very simple and completely adjustable that when I used it I was getting strong spark on all cylinders. I'm not sure what went wrong with the one I made but I would recommend checking out some local auto parts stores for an adjustable one. Mine cost $6.98 and worked great.

 

[fishermanms]

Re: spark tester?

I recently bought one at an auto zone for about $10.... GL..Fishermanms