1992 Stratos 264V - Need prop help

[Dirtbmw20]

I have a 1992 Stratos 264V with a Johnson 115 V4 that I desperately need prop help with. I bought the boat used in April and have been chasing my tail for 3 months now. The boat has NO low end power and struggles like hell to get up on plane barely reaching 1500rpm's. Once someone stands in the front of the boat it will plane off and then has great low end power once on plane. Once on plane the boat runs between 50mph at about 5500prm's. I bought the boat from the original owner and he says it has been like that it's whole life. It currently has a 13.25X19 stainless prop on it (unsure of the name brand) and I also have an aluminum 13X19 prop that was given to me as an extra when the boat was purchased. The boat weighs under 1100lbs and with a 115hp it should shoot out the hole and plane off easily. The boat is currently at a very reputable mechanic and he says EVERYTHING pertaining to the motor is "spot on" and can;t find anything other than the prop that would cause this. He is suppose to be checking to see if he has any extra props for me to try but in the meantime I am reaching out for help. Any idea which direction I should go with a new prop ?? Any help is greatly appreciated. I am also posting this in the "prop" section of the forum.

[Indianabasser]

Tray a raker 20p or a renegde 21p. Maybe there is an issue with a soaked hull? Weigh the boat on a scale and see if it's close. You me be able to try a 17p or 18p, just keep an eye on the rpms

[Dirtbmw20]

Tray a raker 20p or a renegde 21p. Maybe there is an issue with a soaked hull? Weigh the boat on a scale and see if it's close. You me be able to try a 17p or 18p, just keep an eye on the rpms

Wouldn't I want to do down in pitch and not up ??

[Indianabasser]

If you go down your rpm's will go up. 5500 is the max for that motor. Not all props are the same,even if stainless. Not an expert by any means just passing along info I've picked up. I'd start by weighing the boat.