3 to 4 blades prop

[cyrillefrenchy]

hello i own a 20' center console century with a yamaha 130 and a 3 blades 13x19 stainless steel prop in excellent condition.
when i bought the boat used i tried it with the gas tank empty and 1 passenger on board it went on plane easy.
with the 52 gallons tank full and 4 passengers on board it's not the same story...
the hole shot is very bad, it takes forever to plane, even with the weight up front and the trim all the way down
i added trim tabs, a little bit better but still..
the engine is low hours and running strong.
when i hit the throttle wot to get on plane, the rpm goes to 4200 4500 (best rpm for torque, right?)it takes forever to ge on plane, bow in the air,stern very low.
at full speed the rpm is 5500, and well trimed it goes 40mph speedo.
i assume the boat is underpowered, all the others i see have 150 or 175 hp.
i was thinking to switch to a 4 blades prop supposed to give more trust, or trying a bigger prop with less pitch.
any opinion? any idea on 4 blades prop size to start?
thank's
frenchy

[Hamfisted]

I think the max hp rating on that boat is 150, so it should do "Ok" with the 130 on there if it's propped right and not too overloaded. You can view one of their performance bulletins here: http://www.iboats.com/sites/centuryb...cc-f150txr.pdf . Its done with the F150 on there but it'll give you an idea. Then log onto the Century owner's forum and ask questions over there. I don't think you need a 4-blade with that boat unless you're using a jack plate. But I would drop down to something like a Stiletto Performance series 14 x 17 3-blade or there abouts. They did the performance bulletin test with a 14 x 19 on the F150. You'll probably have to try a few props and see what works best. Do you have trim tabs installed? They would help to keep the bow down during hole-shots and most likely improve the overall handling of the boat.
But anyway you'll probably find more useful answers over on the Century owners forum since its a boat specific question.


-Mike

[jb123]

i own a pair of merc offshore 4 blade props and prefer my yamaha salt series better allaround.

[cyrillefrenchy]

hello thank's guys for your replies, all the answers i have are differents.
yes HARMFISTED, i installed trim tabs, they helps a little bit but still.
i will go take a look to the century forums.

[cyrillefrenchy]

hello
i just recieved today my 4 blades prop from power tech, 13x16: huge difference, the boat gets on plane a lot easier, the rpm at wot is still 5400 5500 and the speed is still about 40mph speedo
the stern feel like higher and the boat stays on plane at lower rpm.
maybe a little bit more torque on the steering wheel when not trimed right
i am happy
very big improvement making me forgetting the price ($350)
frenchy