Older tachs says 1998 on the face, there are four wires red, black, green, white, coming through the back and no connection studs, these are monster gauges. Black ground, red ignition, white light, green tach? Ohming out the wires this is what I came up with. [ATTACH=CONFIG]519474[/ATTACH][ATTACH=CONFIG]519473[/ATTACH]

White is lights
Green is tach source, either on negative side of coil or plug into ignition box.
Black ground
Red positive switch source

I got problem working these monster gauges on my boat , I’m trying to make them work with a pair of 300x 2strokes ! Can someone help me with the wiring



they got
green wire
white wire
Black wire
red wire

and The Orange and brown wires uncuts

without cut any wire in the smart craft shows 4700rpm and the gaffrig are 7200rpm

There should be a switch on the back of the tach to change and you need to change it from 8 cylinders to 6 cylinders

no,
no There’s Nothing in the back , just 4 wires , and two out and in ,

cant update photos till I got 10 post

Even the pic in the first post has a sticker that says 4cyl, 6cyl, 8 cyl. I can't make out the rest. The switch could be under the sticker or under a cap/plug.
The Livorsi ones I recently got have 5 micro poll switches under a black cap.

like Griff said, they are under the white sticker in the OP that has perforations in it.

Why does the tach show 1000 RPM with no power?? Shouldn't it show ZERO? Really curious as I need to replace mine which looks identical to yours, but mine shows ZERO and I found a used one that apparently works fine, but shows 1500 RPM.

Please let me know, thanks in advance!

Some gauges will go to zero when powered on, but without power, if they're shaken or moved around much, as in during transit, the needle can certainly be moved off zero. AS long as it goes back to zero with 12V+ and Ground applied, it should be functional.

What he said ^^^^^^^^^