Curiousity.
That's my excuse.
It ain't pretty, but, like my physician said : "It ain't permanent."
The red wire is the pick-up on the plug wire...I put a plastic collar on it and kept it away from other wires and heat with a couple of wire ties.
Routed it through the hinge opening in the glove box, used the VIN plate hole to help route the wire. I always use soft wire to pull things along - if I get the wrong thing I won't do much harm.
Tach is applied with 3M red tape - no holes drilled. Nothing altered.
So now I can watch what my engine is doing - and look for changes as I swap plugs, oil, rollers, sliders, belts, ambient temperature, etc.
Of course you don't need a tach on a CVT scooter - but it satisfies my curiousity of things and when I get tired of it I'll take it out and put in on my push mower.
I'm making chili - but in a quick run it looks like the LIKE is accelerating strongly (enough, for me) at @3500rpm, and I'm idling at @750-900rpm. Chili'll be ready in about 1/2 an hour. This stuff will alter you!