Pontoon prop size? - 27' Pontoon Mercruiser 3.0LX

[DBlume]

We purchased a 1997 Suntracker 27' pontoon last year. It has a Mercruiser 3.0LX/135HP. We recently had to have a bunch of work done, head redone, carb re-built, and replaced the plugs. Mechanic gave it a really nice tune-up so it is running better than ever. Since I know everything is working well with the engine I have decided to make sure the prop is correct. The pontoon can carry 16, we usually have 4-8 adults and 4-6 kids, so I would like to prop for that. Which pitch should I go for, I am thinking 12P? I am hoping the 12P will get me to the top end around 4,800 rpms with a light load, and keep me towards the bottom with a average load. Any issues with such a low pitch prop?

Current Prop - Merc 16 X 16P - WOT 3,700 rpms - 21 mph (GPS) - Average load (5 adults, 4 kids)

Tried - Michigan Wheel 16 X 14P - WOT 4,400 rpms - 24 mph (GPS) - Great performance improvement - Light load (2 adults, 4 kids)

 

[SkiDad]

what you say seems good !

 

[DBlume]

what you say seems good !

Thank you SkiDad!

 

[DBlume]

Any reason I should look at 4 Bladed props?

 

[SkiDad]

i wish i could say I have tried one but haven't yet - i have an odd engine. I hear they are better but not sure if it will help you. I would suggest whatever prop you tried in 14 get that same exact brand / model in 12 if you want to get a predicable increase in RPM.

 

[steelespike]

There 126" prop generated 3700 rpm at 231 with 25% slip
the 14" at 4400 made 24 with 17% slip
I think the motor was held back by the 16 ,14 released it and I think if your going to be doing those heavy loads a 12 will work well.
I think the 14 will have the top speed but may fade faster as you add weight.The 12 figures at 22.6 @ 4800. but should hold up better as you add weight.