Oregon spark tester 42-087

[dennis]

The inline Oregon Spark Tester 42-087 has a clip for grounding, and an uninsulated terminal that hooks up to spark plug wire. Is the other terminal, that sits at about a 45 degree angle and except for the end, is covered by a black insulating material, a ground also? If it is, the spark does not have to jump very far. Also, if wanting to see the spark jump the wide gap, seems to me that one has to be careful that the bare end of the 45 degree terminal does not touch ground. Question is, why is it even there/

[KE4AVB]

Dennis I will look into this when I get mine but it is currently on order and is part of a ship complete back order. My distributor has a shipping policy that is a pain to deal with this time of the year. Would ship back orders when they get them in until my my next order. Got to see the paperwork that comes with the tester.

But meanwhile you can try testing with an ohm meter to see if it is grounded.

Anyway it is not making much sense to me either why a second spark gap at .008" is in place when there is one at .166".

[dennis]

Thanks, KE4AVB.

[KE4AVB]

Boy what a cheap design the Oregon spark tester is. That extra pin just there for looks apparently. I see no use other to ground out the spark.

[bgsengine]

I always figured it was for a way to hook spark plug wire to tester when the straight-in terminal was a tight fit somewhere.. (short plug wire or some such.) I seem to recall some mention of its real purpose at one of the service schools we went to long ago, but it was so long ago I can't remember details - As you may recall the original version was a "donut" of basically High Density Fiberboard with threaded screws ground to points and locknuts to lock adjustment in place and an alligator clip on the ground side. later updates put plexiglas windows on the tester, and then they went to the current version.. I tried to look up the patent for it, but have had no luck finding an original patent, which WOULD describe and detail the true purpose (I believe it is legacy design from when ignition systems used breaker points, magnetos, etc. Possibly something to do with testing the KV strength of the spark...)

[KE4AVB]

Right now that part of the tool is about as useful as tits on a bore hog.

[38racing]

I was using mine last night. I noticed that it was jumping both gaps. I don't recall if that short exposed metal was touched metal.

[dennis]

When I use mine, I think I will put a spark plug boot over the angled terminal that is partially insulated. Most electrical tape is rated for 660 volts. The voltage off of an ignition module or magneto is a lot higher than that.

[dennis]

Make that 600v instead of 660v....typo

[KE4AVB]

Well what a disappointment. Went out to test the new spark tester and I getting no spark indication even on a running engine. Notta a sign of a spark even in a dark room.

And I know I am pretty stupid but even the idiot proof tester doesn't work for me.