Increase speed on a 2003 bayliner 175 bowrider?

[Larken McRorie]

Hello, I have a 2003 bayliner 175 with the mercruiser 3.0L. I am looking for the most speed out of it. I know a little about pitch and all. The tachometer does not work, never looked at why. We have had engine work and removal for the starter but other than that it runs smooth. Anyways, I mostly go out by myself and sometimes have more people in it. Hardly ever pull anybody behind it. I am currently running a 3 blade 14.25x21 pitch prop and it barely does 45 mph trimmed before the boat starts bouncing and needs to be trimmed back down. I want more speed out of it, what prop should I get? 3 or 4 blade and what pitch? Any help is appreciated, thanks.

 

[Rick Stephens]

Probably not much more to be had from a 3.0L. No one can answer your question in more detail unless you know rpm and gps speed at WOT. Fix the tach and proceed from there.

 

[tpenfield]

I'd say the prop is fine, but the engine has to go.

Lots of folks try to perform magic with prop replacement, but the truth is that boats generally come with the right prop on them. You might be able to squeeze a couple more mph out of it playing around with props, but that would be about it.

That prop size seems about all you could put on that engine setup. 4 blades will slow you down. If you are running an aluminum prop, you could try the same size/pitch in stainless steel . . . maybe grab one off of eBay, etc. and then re-sell if it turns out to be a bust.

Also, in addition to engine RPM, you'll need to know the outdrive gear ratio and exact GPS speed.

 

[Scott Danforth]

if your getting a tru 45mph (on GPS, not the dash gauge), then you are doing better than other 3.0's

best I could ever muster with a 3.0 in a boat was a bit over 41.

if you want to go faster, you need more motor.

fix your tach

 

[jimmbo]

Get rid of unnecessary Ballast(Wife, Kids, Mother in Law).
45 from a 3 litre on a 17ft is darn good. More power will be needed to go faster

 

[ezmobee]

Heck yeah. Anything over 40 is real good with a 3.0 on that boat.

 

[garbageguy]

If you're getting 45 mph out of that setup, buy a lottery ticket, not another prop

 

[QBhoy]

If you are getting a true 45mph from the setup...excellent going, I'd say. Buy a stainless of the same pitch (laser 2 be a starter for 10) and you might squeeze a mph or two more.
As mentioned though....it's never going to be a rocket ship with a 3.0. As it is you are probably at the very pinical of performance and should be thankful.

 

[Scott06]

I had a sea ray 170 with a 3.0 for years.As others have said , If you are getting 45 mph or close to it you're doing really well. Another prop isn't going to make go any faster save your money or buy an identical spare.