Osprey Eagle - 90hp Optimax

Shog69 · 20 January 2012, 20:03

Need to buy a new engine and thinking about a new Mariner 90 Optimax to replace my 1997 Yamaha Beto 130. Will the new engine give me the same performance seeing as the 130 was probably not putting out anything like a new 130 would be as it was 15 years old.

Xk59D · 20 January 2012, 21:03

i very much doubt it, those old yams (V4 is assume?) were torque monsters.

i would think even though it was 15 years old it is probably healthy compression wise? if so there will be a notable difference in performance when you change.

you may be better looking for something around the 100-140hp mark to replace.

that said a 5.6m boat would run nicely on a 115 2 or 4 stroke depending on needs/budget etc.

cheers

Mr Flibble · 20 January 2012, 22:49

Hi Shog,
If memory serves me the 90 Opti uses the same engine block as the 115 so is the same weight as the 115 (170kgs). So you get the same weight penalty with less horsepower.
A 90hp TLDI or ETEC is quite a bit lighter which would give you a wee bit more oomph.
For comparison my 115hp Tohatsu TLDI pushes my Ocean Pro 5.5m (3 onboard with dive gear) at 50mph. With 4 divers, 2 x 12 litre twinset, 4 x 12 litre singles, weight belts etc the top speed is down to about 33mph.

The 90 would be slower than your current engine but will burn alot less fuel and still give you a decent cruise speed (prop dependant).
Just don't let Loudy near it with his lump hammer.

Both Opti and TLDI are great engines (same technology), the only gripe I have with mine is to power the compressor etc you need a big battery. Mine won't fit in my console so is housed in a battery box at the stern.

Shog69 · 21 January 2012, 09:10

Also been offered a very good deal on a Mariner 125 Optimax, just the 90 was so much cheaper

Shog69 · 21 January 2012, 09:12

Quote:

Originally Posted by Shog69

Also been offered a very good deal on a Mariner 125 Optimax, just the 90 was so much cheaper

My old 130 would push the Osprey along at 40mph at WOT.

Shog69 · 21 January 2012, 09:13

My old 130 would push the Osprey along at 40mph at WOT on flat seas

Shog69 · 21 January 2012, 09:14

That was with just me and no dive gear

Mr Flibble · 21 January 2012, 13:01

That seems a tad slow to me. Get a TLDI

. I've had mine at 50mph (after tinkling with the power trim) on Loch Fyne heading back to Strachur after diving the Minards. That was 3 up with 2 twinsets and a dug

. What pitch of prop are you using? What sort of revs show at WOT?

With regards to engine choice the following rules seem always to apply.

1. If you decide to go DI 2 stroke, you'll wish you went 4s.

2. If you decide 4s, you'll wish you went 2s DI.

3. If you buy 90hp, you'll moan about the poor performance and wish you'd gone for the 125hp.

4. If you go for the 125hp, you'll greet about the fuel consumption and wish you'd gone for the 90.

4. No matter what make you go for EVERY other brand would have been better/cheaper/more reliable.

You get the jist

There are a lot of mid 5m dive boats out there with 90hp engines. It's a good balance between power and economy. I went 115 because thats what was on the boat. It's nice to have a wee bit more oomph when the boat is a bit heavier. I reckon circa 100hp is ideal for a mid 5m boat.

Anyway you'll need to get at least a 115 to ensure I don't beat you over to Arran in the summer when we head out to dive the Tuscan.

Shog69 · 22 January 2012, 19:09

Looks like the Mariner 125 Optimax is getting purchased now.

Chris · 22 January 2012, 19:17

Quote:

Originally Posted by Mr Flibble

If you decide to go DI 2 stroke, you'll wish you went 4s.

Hmmm not sure I would agree with that

Nos4r2 · 22 January 2012, 20:16

Quote:

Originally Posted by Chris

Hmmm not sure I would agree with that

Depends how much you like the DI 2s noise. Personally, I love it, but I'd swap the Opti for a 300 Verado for free

Shog69 · 22 January 2012, 20:58

Love the noise of a 2 Stroke, and the power.

Mr Flibble · 22 January 2012, 21:54

The point being made was no matter what you choose that little voice at the back of your head will whisper to you telling you that you could have made a better decision.

Yes thats correct, I have voices in my head.

Shog69 · 22 January 2012, 22:43

Should be back on the water next month.

Shog69 · 28 January 2012, 13:43

Optimax 125 getting fitted 6th of Feb

Downhilldai · 29 January 2012, 01:14

Quote:

Originally Posted by Mr Flibble

the only gripe I have with mine is to power the compressor etc you need a big battery. Mine won't fit in my console so is housed in a battery box at the stern.

Have you considered an Optima, or for much less money, a Numax XV24MF?

Shog69 · 11 March 2012, 17:38

Finished running in the new engine today. Very, very happy, plenty power, good on fuel all I need is the correct size prop, WOT and it over revs.

ocrda · 11 March 2012, 23:42

Did you sell your 130 ?