Is it hanging a valve in the head? Check the vacuum when this happens.
If you run the motor with the lower unit off does it still make this noise? When diagnosing problems I always start by trying to isolate
can someone tell me what year BAUJ 1001745 is,Please.
Thanks for your input, I will do a little more experimenting, certainly the engine response using the 8" prop is much sharper.
Checked for spark again this morning and it was still good. Started and ran the motor a few times everything was fine. Checked again this afternoon and