Prop size Merc 4.3L Bayliner Capri 1850 BR

[blue spark]

Does anyone know what size prop to use for all round performance? Mine is a 1992 boat and currently has a High 5 5 blade stainless prop, very impressive looking but not very fast currently 44 MPH and over revving slightly at 4800 rpm - mind you the boat would pull several elephants out of the water with skis! What i'm after is ability to pull 1 skier at a time and top speed as high as possible.

 

[Spidybot]

Re: Prop size Merc 4.3L Bayliner Capri 1850 BR

It really is a matter of compromises. As a rule, each inch you go up in pitch will reduce engine rpm by 200.<br /><br />The stainless HighFive assures good grip and is very ridgid.<br /><br />Stainless is so strong, that hitting obsticles most likely will damage the gears/drive instead of just the prop.<br /><br />Alu is cheaper. Composite aims to combine strenght and value.<br /><br />Check Mercury's prop guide by clicking 'Prop Selector' on this web page <br /><br />Remember that 'weight' is to be understood as all-in-all, ready to go with people, fuel and all.

 

[samols]

Re: Prop size Merc 4.3L Bayliner Capri 1850 BR

Not sure what the specs are on your current prop, but I have a similar size boat and power (18' Sea Ray w/180HP Mercruiser). I currently run a 3 blade Michigan stainless 13 3/4" X 21 pitch and am very happy with performance...approx 50MPH top end at 4800 rpm (still have a bit of throttle left, but Merc recommends max of 4800)and still quite able to pull a skier with a full load on board. When I bought the boat used, it had a aluminum prop, 14" X 19 pitch which also would launch like a rocket but had the same poor top end of 42MPH (@ 4800 RPM) and still way too much throttle left to go. If you want best top end, you could probably get away with 23 pitch but would loose your hole shot, I find the 21 pitch to be a great all around prop for my boat and power combo.

 

[Capt. T]

Re: Prop size Merc 4.3L Bayliner Capri 1850 BR

Blue Spark:<br />By any chance is that HighFive still sitting in your garage or basement? <br /><br />Depending on the specs and condition I might want to give it a good home. Let me know at "tony@nu-waycorp.com"<br /><br />Thanks

 

[JB]

Re: Prop size Merc 4.3L Bayliner Capri 1850 BR

Moving to I/O