I need a cordless tach for 2 and 4 stroke.
Cheap is good.
Bells n whistles not needed.
Need for setting rpm after messing with
carb, governor, linkage, etc.

"mini tach" does that, Was thinking of one for my outboard with tiller, no place to plug one in, that I can see.

Stihl makes one, I’ve had mine a long time but if I recall correctly it was like $89 from madsens

If you can find one of these the work pretty good, a hand held tach.

I like these. Just put a piece of (included) reflective tape on what you're wanting measure. It projects a light and counts flashes per second.

https://www.amazon.com/Digital-Tachometer-Engines-2-5RPM-99-Reflective/dp/B0BYPC2Y5V

I have something like this
https://www.amazon.com/Hardline-Products-HR-8061-2-Tachometer-2-Cylinder/dp/B000FOOAXY

I don't recall if this is the exact brand

the way it works is inductive pick up you hold it near the spark plug on a chain saw , if you want to put it on something like a mower you wrap the wire around the spark plug wire a few times and zip tie or electrical tape in place , then you feed the wire through the slot in the back of the meter. again inductive pick up

slight lag but not bad

had mine since about 2016 I think

I bought one of these when I was setting up a propeller on a 25hp boat motor. Worker well. And bought it from Amazon. Several different ways to configure it for: 1, 2, 4, cylinder engines. 2 and 4 cycle.