Prop size for Delta 5-5 with 75 mariner optimax

Seahunter09 · 20 June 2009, 16:19

Hi. I have just ordered a new Mariner 75hp Optimax for my Delta 5-5. Does anyone know what type and size of prop i should use. I use the rib for diving mainly and towing the donut now and then. Thanks Seahunter09

outboardtech · 20 June 2009, 17:52

19 p will be perfect for that boat . My opinion . Cav plate should be 1 inch from bottom of boat and should perform well .cheers baz

Ian Sharlot · 20 June 2009, 18:34

19p as baz has said but if your going to load it with diving gear or tow, don't be surprised if you need to go down to a 17p

Chris · 20 June 2009, 19:03

I would have thought a 75 on 5.5 would not push much more than 17" on a good day.

I had a 90HP on a 5.3 that would pull a 19 but only just it was more comfortable at 18".

If you can borrow one of each to try first that might be your best bet.

Pete7 · 20 June 2009, 22:10

My money is on Chris for this one, but as he suggests ask to borrow a second hand 17" to try out before deciding.

Pete

Downhilldai · 20 June 2009, 22:14

75hp on a Delta 5.5 sounds inadequate to me. Did you consider a 90 or 115 Opti? Same basic motor as the 75.

Ian Sharlot · 20 June 2009, 22:22

Quote:

Originally Posted by Downhilldai

75hp on a Delta 5.5 sounds inadequate to me. Did you consider a 90 or 115 Opti? Same basic motor as the 75.

I'd agree. A 75hp is going to be minimum, A 90 is only a couple of hundred extra and worth it. A 115 would be nice but I think the price goes up about a grand

Downhilldai · 20 June 2009, 22:43

Quote:

Originally Posted by Ian Sharlot

I think the price goes up about a grand

Are you still a Merc/Mariner agent?

Ian Sharlot · 20 June 2009, 23:41

Quote:

Originally Posted by Downhilldai

Are you still a Merc/Mariner agent?

Yes, but don't have the exact prices with me

Seahunter09 · 22 June 2009, 17:45

[QUOTE=Ian Sharlot;300568] I'd agree. A 75hp is going to be minimum, A 90 is only a couple of hundred extra and worth it. A 115 would be nice but I think the price goes up about a grand [/Q

The engine that was on it was a 70hp Evinrude VRO. That pushed it along quite well. It has always been my impression that a 90hp was just a 75hp with a different carb. Correct me if i am wrong. I had a Delta 5-5 with a 75hp mariner in the mid 90`s for 5years and that went brilliant. Thanks

Downhilldai · 22 June 2009, 18:23

Well, if you're happy with 70-75hp, based on actual experience, then go for it.

Chris · 22 June 2009, 18:40

Quote:

Originally Posted by Seahunter09

The engine that was on it was a 70hp Evinrude VRO. That pushed it along quite well.

So what prop did you run on that and what was your performance.?

Ian Sharlot · 22 June 2009, 19:08

Quote:

Originally Posted by Seahunter09

It has always been my impression that a 90hp was just a 75hp with a different carb. Correct me if i am wrong. I had a Delta 5-5 with a 75hp mariner in the mid 90`s for 5years and that went brilliant. Thanks

Yes, you are right, the 75, 90 & 115 are all the same engines but no longer have carbs, the main differance is a different pcm. you will find that a 75 optimax will be 75hp but with older 2 strokes, a 75 would probably actualy be more than 75hp, this is the case with merc/mariner 2 strokes, not sure on other brands.

As others say if you were happy with your 70, you should be ok with a 75 opti

Turbodiesel · 22 June 2009, 20:58

17" Pitch. Is my guess!!

Turbodiesel · 22 June 2009, 21:00

Try this website. Its usually pretty good, well within a pitch or so!..

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

Seahunter09 · 22 June 2009, 21:23

Thanks foer all of the info. I managed to get in touch the dealer i am oredering off and they told me to get the weight of the boat of Delta. Many phone calls later and it has been agreed a 17" prop is best so thats getting sorted and should be fitted soon. Thanks once again.