Prop question for deckboat

[Royoudo]

Here is what I have

-197 2012 Bayliner deckboat 19ft
-mercruiser 135hp sterndrive
-weighs 2600 ish pounds, 35gal gas tank

-prop that was on it 14.5 x 19p 3 blade could get around 33 mph slow to get on plane hit around 4700-4800 rpm with 6-7 ppl. (Hit a sand bar now toast)

i purchased a 2 4 blade nemesis props one 17p and one 19p

- 19p I took out with 4 adults 2 kids half tank gas, could hit around 4600-4700rpm at WOT and got top-speed 34mph felt great hotshot, faster no wake speed and could cruise planes out at 3300rpm could tube kids no problem.

-17p I took out with 4 adults 2 kids 3/4 tank gas hotshot was amazing tubing no problem, but when cruising had to be closer to 3800-4000 rpms for same plane and speed as 19p prop at 3300rpm. Top rpms where getting close to 4900rpm at WOT top speed about 32mph. This scares me because manufacturers max rpm is 4400-4800.

-so here’s my questions
1. Do I keep both props and when I know I’m taking 10 ppl out use the 17pitch? (Or large adults)
2. Is running at higher rpms cruising with the 17p with less people in the boat ok for the enging? And do I just not go WOT so I’m not hitting 4900rmps?
3. Does anyone have a suggestion for a digital rpm gauge I can use for testing the motor so I’m more accurate than the dash tac? I’m not too confident it’s reading super accurate.

i got a good deal on the 19p prop for 95$ so having both of them I’m not sad about just trying to see what my best case is. Thank you all!!!

 

[Scott Danforth]

first, welcome aboard

second, with a 3.0, its not uncommon to have multiple props. not enough motor on the low end to use one prop. especially on a 19 foot boat weighing 2600# dry. a boat that big should have a 4.3 in it.

when I had my 3.0 in the Avanti, I had a 15p, 17p and 19p on board (my boat was 1650# dry)

for water-sports and trolling, used the 15p
for general boating, tubing, and people hauling used the 17p
for WOT long runs with only 1 or two people, used the 19p

 

[Royoudo]

Wow thank you for the quick response,

good to know im not crazy for wanting to keep both, I have installed smart tabs on the boat and with the 4 blade I have been super surprised with the planning at about 4-5 seconds (good thing the front of the boat is where everyone wants to be) and pulling tubers I have still been surprised how well this 135can do! Once the kids get older I’m sure we will be looking for something with more power!