Just to be sure, you have a gate valve in between the motor and the Bassett tee?
Usually, the tee valve should be able to control all this by itself. A fine mist is ok at idle. Just no raw water dribbling out. You can have it come in sooner than 2500. All motors are different. I think a half a turn on the gate valve will be too little. It shouldn’t be a problem if you start there. Just be ready to start making adjustments.
Did you take apart your old one? Sometimes the spring breaks or gets rusted open. The spring is directional. Sometimes it can be put in backwards.
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