I tapped my wires right on the coil itself.  I removed the wire, pushed the tach wire thru the hole in the tab and pushed the wire back on over it.

Yeah, you wired it wrong.  

I put the + wires on the + side of the coil.  
I put the - wire on the - side of the coil.
I loosened the screw on the bracket that mounted the coil and slipped the ground wire under that.

You are going to have to take the tank off to do this.

The O/W wire is your positive.  Thye B/Y is the negative....it is a 3 wire setup, right?  One positive is for the light and the other for the meter, if it is like mine.

You need to connect at the coil like others said too....and I recommend some wire wrap to keep from wearing through a wire and shorting the ignition

I also put the chrome mount into the front of the handlebar clamp on the left side.  Tightened down the front clamp bolt first and it was good to go.  It isn't "centered", but I didn't want the universal rubber mounting clamp on the handlebar.

Thr 4th wire is for the light.  Hook it up with the pos wire as if it was a 3 wire setup.

Wait a minute....now that I look at it with "2 cylinders" and the little sketch of the distributor....

First of all the "distributor" is solid state on your Savage.  Secondly, the Savage fires on both the compression and the exhaust stroke which is once per revolution (I forgot this).  That is one of those little EPA things to rid any unburned fuel (probably helps backfires too )  There are a lot of bikes that do this.

But the CDI pickup on the rotor doesn't care what stroke the engine is on.  That is all setup with the cam position and it fires on both strokes.  Therefore with my tach, the internal electronics just senses each pulse as an RPM which is correct.

But your tach is connected to the ground side of the coil which then outputs to the "distributor" and to each plug on the positive side.  With the Savage single the physical order is reversed.....Hmmmm.

You know what I'd do?  Warm the engine quickly to fill the carb(not too hot), remove the tank, and connect the ground wires, and then start the bike briefly.  While the engine is running touch the positive lead to the O/W wire connector using a pair of insulated pliers.  If it works the tach will read ~1200 RPMs.  Then you can shut it off, and either finish the wiring or take the unit back.

I have Barons Mini Tach.

...perzact same thing

Drag Specialties:


Barons:

Looks very much like mine, but mine must be "generic" since it has no label.