spark tester

[fisheymikey]

I am sure its easy to answer but im not sure...

here is a spark tester from force but cant find any how to... I edited with paintshop to make easier for a description.

I think I have a weak spark on all cylinders even if I reach 4400 rpms

I assume I set the spark plug wire on #1 then set distance on that pole and install the spark plug also??

 

[alldodge]

Re: spark tester

I am sure its easy to answer but im not sure...

here is a spark tester from force but cant find any how to... I edited with paintshop to make easier for a description.

I think I have a weak spark on all cylinders even if I reach 4400 rpms

I assume I set the spark plug wire on #1 then set distance on that pole and install the spark plug also??

View attachment 219523

Here is a new one from CDI and there is a link of how to use it. The one CDI has is enclosed so things don't blow up by arching over somewhere you don't want it to. I don't think I would use the one you have, may want to get the CDI or basic gap tester.

Spark Gap Tester | Adjustable

Test Equipment Tools | Johnson | Evinrude | Outboards | Basic Power

 

[Jiggz]

Re: spark tester

I am sure its easy to answer but im not sure...

here is a spark tester from force but cant find any how to... I edited with paintshop to make easier for a description.

I think I have a weak spark on all cylinders even if I reach 4400 rpms

I assume I set the spark plug wire on #1 then set distance on that pole and install the spark plug also??

View attachment 219523

The #1 is where you install the plug wire from you CD's or from existing spark plug (you'd better off doing one plug wire at a time). #2 is where you set the gap by turining the brass screw in or out, usually I start with 1/8" and increase to about 1/4". But if you have a strong blue spark at 1/8" or even better at larger gaps, that means you have good spark. The alligator clip attaches to ground. NO NEED TO INSTALL THE SPARK PLUG INTO THE SPARK TESTER FOR NOW. If you want to test the actual spark at the spark plug, instead of connecting the plug wire to the brass screw, install the spark plug into #3 with its plug wire, attached alligator clip to ground and you should see actual sparks on the spark plug the same way it is installed in the cylinder. Hope that helps.

 

[fisheymikey]

Re: spark tester

The #1 is where you install the plug wire from you CD's or from existing spark plug (you'd better off doing one plug wire at a time). #2 is where you set the gap by turining the brass screw in or out, usually I start with 1/8" and increase to about 1/4". But if you have a strong blue spark at 1/8" or even better at larger gaps, that means you have good spark. The alligator clip attaches to ground. NO NEED TO INSTALL THE SPARK PLUG INTO THE SPARK TESTER FOR NOW. If you want to test the actual spark at the spark plug, instead of connecting the plug wire to the brass screw, install the spark plug into #3 with its plug wire, attached alligator clip to ground and you should see actual sparks on the spark plug the same way it is installed in the cylinder. Hope that helps.

ok that's what I thought but I think I read some where I need to gap it at 7/16 to be confirmed I have a good spark...

is that true or 1/8 to 1/4 is fine

thx

 

[Jiggz]

Re: spark tester

To be realistic, most surface gap spark plugs measure approximately 0.051" or 1.3mm which is about half of 1/8" or about 1/16". In short, a 1/8" gap with blue spark or better yet 1/4" gap is more than enough sign you have a good strong spark. Mind the keyword, "blue" spark. With old outboard engines using gapless plugs, it will be very hard to achieve a strong blue spark at 7/16" or more gap. Maybe on regular automobile ignition system or newer outboards using newer electronic ckts but not necessarily on 2-cylce Force engines with old technology.

 

[jerryjerry05]

Re: spark tester

A healty system will allow a spark to jump the 7/16
Like Jiggs says the permagaps only spark a very short distance.
The idea is the stronger the system the farther the spark will jump.
The spark should jump that distance and all the plugs should have the same color spark.
The first thing to do is check the compression.
The 4400 rpm's is a sign somethings not right??
4400 could be the prop's wrong or the boats too big or ??????

 

[oldboat1]

Re: spark tester

When I first joined the Antique Outboard Club a number of years ago, a local member gave me a spark tester as a welcoming gift -- a racing spark tester, as I understood him. It's a plug with a clamp welded to the threaded area. You attach the engine plug wire in the regular way, and clamp to a bolt or engine part within reach to give you a ground. (I never did it the old fashioned way -- by hand -- because I was always a little afraid of getting a jolt when handling the plug.) Anyway, it is easy to see if the spark is weak or nonexistent. A strong spark is likewise real easy to see. I think you could duplicate the method by winding bare wire around the threads on a plug, and securing the end to some part of the engine block, then briefly cranking with the plug attached to the plug wire. Remove the other plugs first, and make the test without too much overhead light so you can be sure to see the spark. (and keep the plug away from the plug holes or any fuel or fuel vapor source.)

I'm not sure how you can determine that there is no spark at high rpms without risking engine damage, although maybe you have some other analyzer that allows you to do that.