performance of 130 hp mercruiser in 16' boat?

[BF]

Hi all,

I'm considering buying a 1990 Sea Ray 160 (overall length 16'9"). It's in near mint shape and has very low hours. I haven't been able to test drive it yet, and will have to make a big drive to get there (basically have to decide whether to buy before bother to drive there). It's got a 130 hp 3.0 mercruiser for the powertrain.

I'm very familiar with O/B boats, but this would be my first I/O. My dad used to own an older 120 mercruiser (2.5L) in a similar sized glastron, and it was usable, but a bit of a slug. It was probably the equivalent of having a tired 80 hp OB on the back. His would do about 38 or 39 mph. I'm not looking for a speedy boat... just a family hauler that will be used for taking small kids tubing and skiing on our smallish lake. I've been watching for about a 17' bowrider with a ~115 OB... but then I saw this boat come up and it looks to be in really good shape.

So, what performance should I expect from a 130 hp mercruiser in a ~16' bowrider? Should I expect to see a bit of a difference between the 3.0 L and my Dad's old 2.5L ? Do you think it would be about equivalent to a 115 HP outboard or so?

I'm aware with some of the maintenance prob's with I/O's, but is a 1990 Alpha One a reasonable decent drive? Any better (or maybe the exact same?) as a 1972 120 hp outdrive (which is what my Dad's was)?

There are so many 3.0 Alpha one's out there, I'm hoping that means they can't be horrible.

Thanks for your $.02

 

[ezmobee]

Re: performance of 130 hp mercruiser in 16' boat?

I think the 3.0 in that boat would perform great. I think your assessment of it being equivalent to about a 100-115 outboard is correct. My uncle has a 3.0 in a 1995 17' SeaRay and has been using it primarily for watersports since new. It does great.

 

[IVAZ]

Re: performance of 130 hp mercruiser in 16' boat?

Although I don?t know the weight of that boat it is fairly small. I bet it will perform just fine.

 

[Bart Sr.]

Re: performance of 130 hp mercruiser in 16' boat?

My '93 Sierra is 16/17 ft with 3ltr 130 horse Yamaha gets along very well.I have pulled two skiers with two in the boat with no problem.

 

[BF]

Re: performance of 130 hp mercruiser in 16' boat?

well, thanks for the encouragement.... I took the plunge and bought the boat with the proviso that the owner and I do a water trial prior to sealing the deal and it shows the boat to be in good working condition. The owner had no problem with this as he assures me there are absolutely no issues with the boat... no knocks or noises from the drive, and the motor runs perfect etc.

I figure the deal is good enough that if I don't like it, I can probably sell it without a problem and not lose money.

Now I get to do some reading about 3.0 130 hp mercruisers! from the few posts I've already seen, I can tell that the Apha drives don't like being spun at rpm's greater than 4800 or so.

Here's my prediction... that power wise it will be fine for my needs and with a light load it will top out around 44 mph if it's prop'd correctly. We'll see how close my guess is.

 

[BF]

Re: performance of 130 hp mercruiser in 16' boat?

My '93 Sierra is 16/17 ft with 3ltr 130 horse Yamaha gets along very well.I have pulled two skiers with two in the boat with no problem.

Hey Bart... nice boat. Is the yammie 3.0 the same motor as the mercruiser, or a different animal? For your pulling power, do you use a lower pitch prop, or is it just how it pulls with the pitch that reaches proper rpm's at WOT? What's your top speed?

thx!

 

[Bart Sr.]

Re: performance of 130 hp mercruiser in 16' boat?

Hey Bart... nice boat. Is the yammie 3.0 the same motor as the mercruiser, or a different animal? For your pulling power, do you use a lower pitch prop, or is it just how it pulls with the pitch that reaches proper rpm's at WOT? What's your top speed?

thx!

Well I am not a motorhead and this is the only boat I have ever owned so I honestly couldn't make an informed comparison.

I run a 14.25 X 19 prop and without skiers it leaps out of the hole and runs 48-50 at 4800 rpm.

I am very happy with the performance.

I will post pics when I can. Might be a couple of days though.

 

[BF]

Re: performance of 130 hp mercruiser in 16' boat?

I run a 14.25 X 19 prop and without skiers it leaps out of the hole and runs 48-50 at 4800 rpm.

I am very happy with the performance.

thanks for the specifics of the prop and performance.... Is that 48-50 speedo or by GPS? It seems great.. almost too good to be true. I have a 16' ski boat (glastron CVX) with a merc 150 OB. On that I swing 19" pitch 3 bladed aluminum prop near 6000 engine rpm, and it 'only' hits low to mid '50's. (that's speedo mph, so could be off) It's primarily a ski machine though and can literally jump out of the hole. Also, it starts chinewalking pretty bad by the mid 50's anyway. I don't expect my new boat to have anywhere near that performance, but it would be nice if it wasn't the aquatic equivalent of a chevette.

I'm not so overly worried about top speed, but it gives an indication about whether the power is adequate. The fact that you're happy with yours is encouraging.

 

[BF]

Re: performance of 130 hp mercruiser in 16' boat?

UPDATE

So, after a couple weekends booked up with "other" stuff, I finally got the boat to the lake....

But, here's what I did first:

- The gimble bearing was obviously dry b/c it was making some noise, the noise went away when I greased it. I could faintly hear the U joints too. I figured I needed to catch up on neglected maintenance, so I pulled the drive and ended up replacing the gimble bearing and seal anyway. There was no play, but it didn't feel as smooth as it should have.

- The bellows seemed to be in very good shape so I left them.

- The U-joints seemed good too, (but needed greasing) so I just greased them.

- I serviced the raw water pump. It needed it BAD. Tip of one vane of the impeller was broken off, and others were cracked and about to go. Catastrophe averted.

- Had the prop re-conditioned.... One blade was dinged up and marginally bent. Now it's like new.

- New spark plugs.

- Cleaned interior well.

So now as to performance: The boat runs really well. Not underpowered at all. It has a 14.25 x 21 merc aluminum on it, and it pulls surprisingly well out of the hole, and tops out at ~45 mph at 4700 rpm with trim and a very light load in the boat (just me and 1/4 tank of gas). That's speedo mph not gps. Seems about perfect to me. It easily pulled my small kids on double tubes (2 tubes at once). Loping around at ~3100 rpm and ~22 mph.

Motor & drive train is very quiet at idle... just nice motor noise while underway. Wifey likes quietness compared to our older outboard boat. All things in the boat function as they should... power steering takes some getting used to (I'm used to torque steer). Tach occasionally gives whacky readings... I'll need to trace the wiring and look for a loose connection.

Anyway, so far looks like a winner!

 

[BF]

Re: performance of 130 hp mercruiser in 16' boat?

Here's my prediction... that power wise it will be fine for my needs and with a light load it will top out around 44 mph if it's prop'd correctly. We'll see how close my guess is.

Turns out I was about on the money!