3.0 140hp performance?

[jedimaster]

Just wondering how fast others are able to go in there boats that are running a 140hp 3.0 mercruiser? I know its very hull and prop specific, but if you could include the basics, I just want a rough idea of how well my boat is performing.
Not sure what the prop pitch is(How can I measure it)
but I have an '88 glastron bowrider 17.5 feet and I go about 45mph full throttle on a calm lake by gps.

 

[tommays]

Re: 3.0 140hp performance?

Thats about as good as gets other than a few newer go fast stingray hulls with 8 gallons of gas and a 100 pound driver


Tommays

 

[vipzach]

Re: 3.0 140hp performance?

I can hit about 42 mph with the wife and I in the boat. Rpms around 4500 and I have a 17p SS rapture prop that is vented. You should have some numbers stamped on your prop somewhere, look around the hub on the inside of it.

 

[harveje]

Re: 3.0 140hp performance?

1990 1750 caravelle classic 19P Al 3 blade vented 43 mph GPS with wife and one kid, calm water

 

[jedimaster]

Re: 3.0 140hp performance?

I know this is an old thread but I am finally puttingon a different prop. I was running a 7 pitch aluminum at the time. I have addes some weight and have gone down to 42 mph. Going to try a 19 soon. Anyone else have any 140 hp mercruiser speeds?

 

[mhunt]

Re: 3.0 140hp performance?

I just bought a 1995 sunbird with the 3.0 rated at 150hp. 17' bowrider. GPS'd @ 43 mph. 15x17 prop

 

[whywhyzed]

Re: 3.0 140hp performance?

My old 21.5' Bayliner Cuddy with 4 people and gear, full tank of fuel. 15Pitch prop 32 mph top speed.
With just me, no gear and fumes in the tank runnin' downstream- 17 Pitch prop - 36mph

 

[moser42]

Re: 3.0 140hp performance?

I had a 1989 17.5 ft Thundercraft bowrider, with a 3.0L 130hp OMC cobra
When it was bran new, it did about 47mph on radar, and the last year I had it (2004 so it would've been 15 years old) it did about 44mph on GPS. Sounded cool too! Also pulled up skiers and went tubing with no problems.

 

[180Diablo]

Re: 3.0 140hp performance?

Well I just bought myself a 1993 Mariah Diablo 18ft in September last year (first boat purchase). This past weekend I was finally able to get on the water and run it (mother nature had rained us out the past few weeks).

I dont have gps, but according to the gauge it said about 35-36mph going about 4500-4700rpm range. Thats with myself, girlfriend, neccesary gear only and somewhere around 3/4th fuel... in whatever size of fuel tank it has. It was sunny middle of the day 25c's (or around 80F), light wind and a little chop. Stock prop also I would imagine, it looks like has been on there for a few seasons (paint has worn away off the prop).

Personally, having never owned a boat this fast, I thought that the "gauge" 35mph range was plenty fast enough for what I want to use it for. Whether it was correct or not. The previous boat we were allowed to use, were a late 1970s Cutter with a oil leaking 35hp Merc and a 1960s or 1970s range 6hp Johnson with one heavy arse fibreglass open 3 seat boat.

 

[QC]

Re: 3.0 140hp performance?

Going to try a 19 soon.

Are you reaching 4600 RPM as is? If not, I think you're gonna be unhappy

 

[wakeboarddude]

Re: 3.0 140hp performance?

I have a 17'5' bowrider with the 3.0L. With a 15pitch 4blade prop I'll do 35 at about 4600rpm. Does anyone know what max Rpm should be?

 

[QC]

Re: 3.0 140hp performance?

I think Merc spec went to 4400 - 4800 WOT RPM range in 1983, same today. Before that it was was 4600. For some reason OMC went longer at 4600 . . .

 

[Bondo]

Re: 3.0 140hp performance?

I think Merc spec went to 4400 - 4800 WOT RPM range in 1983, same today. Before that it was was 4600. For some reason OMC went longer at 4600 . . .

Ayuh,........ And what's a mere 200rpms amongst Friends,...........

The 3.0ls are running at their Ragged Edge at 4800rpms........
They're not near as tolerent as the V-motors if you start brushing the 5000rpm Mark...........

 

[wakeboarddude]

Re: 3.0 140hp performance?

Thanks, sounds like I've got my prop pitch dialed.

 

[180Diablo]

Re: 3.0 140hp performance?

4500rpm is where I think my boat runs best, no need to keep it locked at WOT when using it. 1500rpm when cruising up the river system. Fast enough to move along, my wake isnt big and also its not overly noisy from the engine once u pass 1700+rpm.

 

[jedimaster]

Re: 3.0 140hp performance?

Currently I hit about 4700rpm's and climbing but I chicken out and don't wanna over rev it and blow something up.
I am currently looking at a 19 pitch quicksilver cleaver. Are they any good?

 

[wncrjb]

Re: 3.0 140hp performance?

My 1988 18 foot bowrider with a 17P will run about 38 MPH at 4600 with 4 people in it.

 

[sikz3]

Re: 3.0 140hp performance?

You all all killing my 3.0 omc. I got next to a nice wakeboarding boat at at about the same pace as me he says I was doing 27mph with me (225lbs.) and buddy(175lbs.) and full tank of gas.

 

[jedimaster]

Re: 3.0 140hp performance?

I found this last night. I entered my boat type weight etc.. and it said a 19 pitch cupped is optimal for top speed with a 14" diameter. I have also read that if your running a 19 pitch cupped You can run a 21 pitch cleaver and gain top speed but have the same bottom end do to it slipping and generating rpm's faster. I am going to buy a 21 pitch cleaver and see how it goes.

http://appcenter.mercurymarine.com/propSelector/home.do

 

[whywhyzed]

Re: 3.0 140hp performance?

You all all killing my 3.0 omc. I got next to a nice wakeboarding boat at at about the same pace as me he says I was doing 27mph with me (225lbs.) and buddy(175lbs.) and full tank of gas.

Need to do some troubleshooting if you think the wakeboard boat speedo was accurate.