Equus Tach on G16...again....

[MattMPA]

Okay guys and update...and I'd be glad to hear your thoughts.

I got the NGK splice, a new plug boot and a length of wire from my local motorcycle shop.

I lengthened the spark plug wire to about 12", with the splice being very near to the engine. (I cut the original wire as close to the spark plug as possible) Engine runs fine.

This new wire is a bit loose on the inductive pickup....so I've tried some electrical tape around the wire to make the inductive pickup ears hold better. I've wrapped the area completely under the pickup. I've made up a tubing "sleeve" with a notch for the pickup to "see through". I've also used nothing and have moved the pickup all over the length of the wire.

I get slight differences...but it just won't read above about 3500. It gets there and then drops to 0.

The odd part is that it worked fine when I extended the wire with a spark plug testing tool I have. Could this wire be a problem? Or, the new NGK sparkplug connector? The new plug connector required removing the screw-on top of the plug to connect...but I can't see how any of this is an issue.

Finally...with 12" of spark plug wire...I've moved the pickup from one of the wire to the other...and in the middle. The tach consistently shuts off at 3500 RPM.

Here's a pic of the original spark plug connector where you can see a cross section of the original wire...and the new wire.

[MattMPA]

Is there any end to the updates...

I played with this just about all afternoon. I took apart the tester I had to try the spark plug connector/wire that had worked before. Same as above.

I've also shortened the new wire (as seen on the left above) and nothing seems to change.

I'm still wondering if the white insulation in that new wire could be a problem....

[sho305]

They don't like to read when they get interference, from other or the same plug wire. Getting them away from other parts of the ignition seem to help (longer wire). Think you will have to keep playing around with it. Not sure a grounded shield around the pickup would help or not, try wrapping foil and grounding it. Also be careful where the return wire to the tach goes, keep it away from electrical things.

[dbmachine]

Have you considered the tiny tach brand.. Couple on eBay for 30$

[MattMPA]

sho305...I am going to experiment with it as I had it working perfectly with a different type spark wire for testing.

dbmachine...I saw the TinyTach...just wasn't what I was wanting. Thanks!

[sho305]

I have a $15 tiny tach deal from ebay. It works but is slow to react/update. It takes a couple seconds to change reading and I can speed up much quicker than it does. I have to redo the pickup as it stops reading at 5500 right now and I hope that is the problem. It works well up to 5K rpm, tells me engagement and cruise rpm, etc.

[MattMPA]

I've been thinkin'....

As mentioned above, mine worked fine all the way up the RPM range when put onto the spark tester. I wonder if the reason mine worked that way was some light "load"...the flashing light bulb?

I'm thinking of how a timing light won't work if the plug isn't firing....