Question about balancing rotating assembly

I balance a lot of single cylinder Kohler 16, 14, 12, horse motors. A lot of them are strokers with counter weights so big they have to bolt on because they won't fit through the hole in the block.

It is definitely not an exact science. The last one That I did, had already been balanced at another shop. The guy said it would shake his fillings out. I weighed everything, made up the bobweight and spun it. It was only about ten grams off, and that is subjective, as there are different schools of thought on what percentage to use.

I corrected it and when he picked it up I told him that I probably didn't do him any good.

He called a couple of days later and said it was great. I was amazed, 10 grams is not much, but they really zing those little motors. Garden tractor pulling.

I use 65 Percent on the bob weight in the bigger bore motors, a little less, but never less than 62 percent in the smaller stock class motors.

The one nice thing about those motors is that you don't have to match weigh when there is only one of everything. it is also easy to put in mallory when you can unbolt the counter weights.

This doesn't help the OP, but just adding to the fact that balancing is not an exact science and sometimes you have to rely on what you have found to work.