Hmm.. never heard about exagerated porpoising on a
Arrowstreak GTS with 130 HP
( I presume it is the Arrowstreak 160 GTS )
Could it be that the boat is not getting properly onto plane ?
If so, you could try a propeller with a lower pitch to see if it helps.
Allthough a lot of the members here are far more skilled in
setups than I am, you are allso very welcome to post your qustion in this forum : www.fletchermarine.com/forum