Not sure on your knock meter, but the ones that are normally fitted to cars, just bold to the block, and measure detonation as a whole across the whole engine opposed to individual cyclinders. They basically measure vibration.
They normally have a big range, and you just keep an eye on it. Normally running might see a number in the low hundreds, while a big knock might be around 300 plus (audible pinging).
Not sure how one would go on a 2stroke bike though.
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