What size outboard on 5.5 mtr plate

 Hi guys

I have a 5.5 mtr Searider that currently has a Johnson 115hp 2 stroke

I am looking into repowering with a 4 stroke, either 135 or 150 hp if I can get away with it

The hull does not have an ABP and I am just talking to a marine builder about getting it specced for one.

What 5.5 mtr hull do you guys have,  what size 4 stroke and are you happy with the power

Cheers 

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ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

150 Merc FTW

Wed, 2021-01-06 19:50

 Or 130 Yamaha. or 140 Suzuki, plenty of choice, the Merc will outperform either of the others, check the weight allowed on your transom, Merc is only a little heavier than the other two lesser HP, lower capacity jobs.

lightest version of each- Merc 150 208 kg, Yamaha 178 KG, Suzuki  186kg. Merc is 3000cc displacement suzuki 2044 cc, Yamaha is  1832 cc. Merc as a clear displacement advantage , for little more weight, this comes through as grunt and the ability to swing a bigger prop, and feel load less at the same time.

Your Johnno was likely about 140 kg. 

sea-kem's picture

Posts: 13154

Date Joined: 30/11/09

 Nice info Ranmar 

Wed, 2021-01-06 20:59

 Nice info Ranmar 

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Love the West!

Posts: 577

Date Joined: 28/11/16

Going from an old 115 to new

Thu, 2021-01-07 05:45

Going from an old 115 to new 150 is a huge jump in power. I would be hesitant to put an additional 70kg hanging off the transom. A 130 would be perfect 

Posts: 35

Date Joined: 22/08/14

 Thanks for the feedback, yes

Thu, 2021-01-07 06:56

 Thanks for the feedback, yes I am thinking the Merc 135 may be a better choice

Am just concerned that the 4 stroke won't have same grunt if the 2 stroke but I haven't actually been out in a boat with a 4 stroke 

Just waiting to see what the assessor suggests as max hp

pelagicyachts's picture

Posts: 1113

Date Joined: 23/02/11

hp is hp.... 115hp two

Thu, 2021-01-07 07:51

hp is hp.... 115hp two stroke is same as 115hp 4 stroke :-)

4 strokes have come a long way in the last 15/20 years the early ones did not have the hole shot of two strokes which is where the misconception has stuck that you need more 4st hp than 2 stroke to get the same performance
Any current model 4 stroke (same hp or higher) is going to outperform your current motor

Posts: 776

Date Joined: 25/05/12

 I've got twin 75 etecs on my

Thu, 2021-01-07 06:37

 I've got twin 75 etecs on my 5.8 ocean hull not much bigger boat but it is a 6mm hull...2x75 weighs 290kg so you would be close to a 150  on the searider I'd assume 

i get around 37 knots tops 

Posts: 76

Date Joined: 25/03/13

150 Merc

Thu, 2021-01-07 07:39

 I put a 150 Merc on my 5.5m Fish Hunter. it's awesome

rob90's picture

Posts: 1121

Date Joined: 06/02/13

 Nice rig, ive got a soft

Thu, 2021-01-07 08:36

 Nice rig, ive got a soft spot for those sea riders, with a new motor it will be a weapon. 

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 Hi my name is rob............. and I'm a........... fishaholic

Posts: 35

Date Joined: 22/08/14

 Okay got word back from boat

Thu, 2021-01-07 20:02

 Okay got word back from boat builder today that they will provide an ABP that certifies 150hp and 6 people

Old Johnson came in at 177kg and Mercury 150 is 208kg

Should level boat out a bit as it sits a little bum high currently

Been told there is a wait of up to 3 months to get the new motor

 

Posts: 577

Date Joined: 28/11/16

Should work out nicely then.

Thu, 2021-01-07 20:21

Should work out nicely then. It’s going to be a rocket ship haha. What does a 150 set you back?

Posts: 35

Date Joined: 22/08/14

 That's the bit that bites a

Thu, 2021-01-07 21:00

 That's the bit that bites a little

The Mercury comes in at around 21k fitted with a SS prop and higher spec electronic gauges

Still it will be my last boat and the new motor should see me out given that the old Johnson lasted for about 24 years 

 

Posts: 577

Date Joined: 28/11/16

Yeah for sure but we’ll worth

Fri, 2021-01-08 06:04

Yeah for sure but we’ll worth it. I’m looking down the barrel in the next couple of years to buy a new 250  

Posts: 12

Date Joined: 12/09/13

 Mate ive got a 560

Fri, 2021-01-08 06:32

 Mate ive got a 560 trailcraft sportscab its got a 90hp 2 stroke merc on it im looking to up grade to a 115 4 stroke mercury i would of fort a 150 on the back would rip the arse end off if not having a heart attack over the price of a 150 first

Posts: 35

Date Joined: 22/08/14

 Hi TilesYour trail craft has

Fri, 2021-01-08 07:21

 Hi Tiles

Your trail craft has a max hp rating of 135 from factory and that is with a 2.1 mtr beam

The Searider has a 2.4 mtr beam so I imagine weighs a little heavier again

I am not one to run my boat at WOT much anyway, let's be honest our sea conditions don't often allow it

What I am after is the ability to handle a bit more weight when I take a few mates out

I also figure that economy and engine life will improve if I am not running the motor high in the rev range all the time

And yes the price is up there but I can justify it

Cheers

Posts: 12

Date Joined: 12/09/13

 Hi KatmanFew good points

Fri, 2021-01-08 08:57

 Hi Katman

Few good points there still the price of boat motors does my head in

ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

Yes, you can buy a whole new car

Fri, 2021-01-08 09:09

 For the price of a modest outboard. Economies of scale, I guess. 

straith's picture

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Date Joined: 25/11/13

 Lol last car i drove to

Fri, 2021-01-08 18:31

 Lol last car i drove to rotto sank.... just sayin

ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

well, you gain points for at least trying

Fri, 2021-01-08 19:58