2x 50hp outboards on a 5.4 Searider?

Ruari 29 · 18 October 2011, 21:40

Hi guys, I currently have a 50hp mercury on my SR, was wondering if anyone had fitted 2 outboards on a 5.4 SR?
Its just a bit sluggish, bought the 2004 4stroke 50hp with the boat and it runs well, could I add a second 50hp instead of buying something bigger?

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chewy · 18 October 2011, 21:42

I think it'd swamp the back end if you did. Can you physically fit two on?

Turbodiesel · 18 October 2011, 21:44

I have fitted quite a few twin 40hp's on 5.4 seariders. But they were 2 stroke enignes. Not sure if the transom will hold up a pair of 50's.

yoyo · 18 October 2011, 21:57

When there are 2 engines on the back in your case adding up to 100hp it is said that there is only about 2/3 of the power of a single 100hp engine due to the addition drag of the second engine etc. This means that you would actally be increasing the power on your RIB by aprox 15hp only

......Another option would be to sell your original 50hp engine and buy a larger single engine 90-100hp.

Of course there are other benifits to be considered in having a twin engine set up.

Ruari 29 · 18 October 2011, 23:11

Quote:

Originally Posted by chewy

I think it'd swamp the back end if you did. Can you physically fit two on?

Looks like 2 would fit haven't measured yet, Im bit worried about the weight on the transom.
Ive just re-wired controller, new control cables and steering on the 50hp + fixed an electrical fault, now runs great after 40 +hrs work hence why I would rather add a second?

Any pics of the twin 40s on the SR?

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diverbert · 19 October 2011, 07:38

twin 40 is ok fine 34knots but 2-stroke
twin 50 4 stroke is to heavy and wouldnt do that if i were you. 90hp suzi is super!!!

grtz
Bert

Neil Harvey · 19 October 2011, 08:28

Quote:

Originally Posted by Ruari 29

Any pics of the twin 40s on the SR?

try searching PeterR posts, he has/had one with twins, hs pics might be in the gallery show us your searider thread

9D280 · 19 October 2011, 09:12

[QUOTE=yoyo;426063]When there are 2 engines on the back in your case adding up to 100hp it is said that there is only about 2/3 of the power of a single 100hp engine due to the addition drag of the second engine etc. This means that you would actally be increasing the power on your RIB by aprox 15hp only

......Another option would be to sell your original 50hp engine and buy a larger single engine 90-100hp.
QUOTE]

Search for "twins drag cube" and my ID. I'm fed up typing this........

Ruari,

Twins on a 5.4, not a huge problem, unless you have a transom cut- out? Twin 4- stroke 50s you'd best fill the rear toob sections with helium! Weight will be your biggest issue with that setup. Kev on here also had a Twin 40 setup, and could tell you more about it. Did I see twin 40s on sale in the bits'n'bobs section?

Ruari 29 · 19 October 2011, 09:25

Thanks all for the advice its decided next year will have to upgrade to a bigger lump.
Everyone here on the Isle of Mull has new suzuki outboats seem popular.
90 sound fun

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9D280 · 20 October 2011, 10:12

.....Nothing to do with Ardoran of course!

Ruari 29 · 21 October 2011, 12:16

Yep probably

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GordyP · 21 October 2011, 12:31

One of the seariders at the sailing school I worked at years ago had a 5.4 with twin 50's, they were 2 stroke yams. Boat went well with them and would carry a lot of extra weight.

Modern 4 strokes might be a bit of a squeeze.

Maximus · 21 October 2011, 16:10

Quote:

Originally Posted by Ruari 29

Thanks all for the advice its decided next year will have to upgrade to a bigger lump.
Everyone here on the Isle of Mull has new suzuki outboats seem popular.
90 sound fun

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Sounds like the way to go!

spartacus · 21 October 2011, 20:45

Quote:

Originally Posted by GordyP

One of the seariders at the sailing school I worked at years ago had a 5.4 with twin 50's, they were 2 stroke yams. Boat went well with them and would carry a lot of extra weight.

Modern 4 strokes might be a bit of a squeeze.

I spent over a year looking for Yammie 50G (2-stroke engines). They're very rare, as in lottery number rare, rocking horse poo, hen's teeth, you name it. Good suggestion though!