Boat Speed....What should I be expecting

[sammtoon]

I have a pontoon 24ft.....last season I had a 65 Merc on it, I swapped it out with a guy for an Evinrude 75HP. Before spring I am going to add a 4 blade to it......this should push better shouldn't it, and maybe let the kids tube a little? I hope to be upgrading to a 100HP which i am sure will be much better...thanks for the heads up

[mike]

I would not think it will be a speed machine but you could probably tube behind it just fine! Be sure you check the motor rating on the toon first before getting too crazy!

[bug73]

My boat is a 21 footer witha 75 merc, I get anywhere between 18-21 depending on prop, how many people and what the water is like, if that give you any idea. Im not sure what advantage the 4 blade prop over 3 blade is, I got the most performance boost when I changed props to the next step lower then what was stock, cant remember the numbers at the moment

will look next time Im out shoveling this damn snow...

[dockholiday]

Must do your boating on Lake Allatoona. Don't think I would go to the 4 blade, which would give you more bite or hole shot, but sure don't think it would help on top end. Had a 90 merc on my old 24' two log boat and didn't have a speedo but my guess was the very low 20's at best. Should be fine to do some tubing with as is.
doc

[sammtoon]

Thanks for the heads up, the only reason I was changing to a 4 blade was because it was going to help the umph getting it outta the hole. Doc yes I do 98% of my boating on Allatoona, I live within ten minutes of the lake so thats were I go. Thanks.....for the insight!