if i change my prop, would it help my speed

[jimdogg]

1989 sea ray 200,, 4.3 mercruiser,, alpha one stern drive.. 175hp,, rec rpm is 4400 to 4800..

at wot i get about 43mph at 4900rpm, with 2ppl, it has a 14 1/4 21p quicksilver alum prop thats in pretty good shape.

i recently bought the boat and i dont know what kinda speed it ran before, but i was hopeing i could change the prop and get a lil more speed out of it, i use the boat just for cruiseing and pulling a tube,, usally have 2 to 6ppl and it has a 31gal tank. boat weighs 2300 dry

i put new plugs, wires, dist cap and button, new fuel filter on it and had the carb rebulit about 2 months ago

its my first boat so i dont really know much about them, any help would be great,,, thanks jim

 

[hwsiii]

Re: if i change my prop, would it help my speed

What is the gear ratio for your outdrive.


H

 

[jimdogg]

Re: if i change my prop, would it help my speed

the gear ratio is 1.84:1

 

[hwsiii]

Re: if i change my prop, would it help my speed

You are showing a 19% prop slip right now so with the right prop you should be able to get another 4 or 5 MPH out of it.


H

 

[jimdogg]

Re: if i change my prop, would it help my speed

what do u think i should try

 

[truckermatt]

Re: if i change my prop, would it help my speed

I have the same motor as you in a similar sized boat..... mine run 4700prm WOT at 44mph (GPS)... with a quicksilver, 14.25"x 21p 3 blade alum...

If your at 4900 rpms, then i would suggest a 14"x 23p prop , and that should lower your rpms by about 200.. and will get you more top speed.... but you may lose some hole shot....

Was your speed GPS or speedo?

I would stick with the 21p prop, that way you have the extra power you need when the boat is loaded...

 

[jimdogg]

Re: if i change my prop, would it help my speed

the speed is by speedo

 

[hwsiii]

Re: if i change my prop, would it help my speed

Jim, buy a 4 blade Solas Amita 21" pitch prop here at Iboats for about a $ 100 and you will be very happy with the difference in performance.


H