Engine upgrade - re-survey?

[stuozfish]

Hi All
It's time to invest in a new engine on my Southwind UB670 centre console longboat.
The current engine (Evinrude ETEC 90hp @ 152kgs) is costing too much in repairs so I'm targeting a new Yamaha 115hp @ 176kgs.
However, the Southwinds compliance plate states the MAX engine hp is 100hp and MAX weight is 185kgs.
The insurance company wants me to have a marine surveyor assess the boat and produce a letter change for the larger engine at a cost of $500, if i want to remain fully covered.
The surveyor cannot guarantee the boat will pass the assessment.

My questions are;
Is upgrading from a Yammie 100hp to 115hp worth the $500 cost and risk? Will i really notice that much difference? The dealers say I will !!
Anybody know of a UB670 or similar with a bigger engine - any issues?
The transom is about 3-40mm of solid glass - woudl this be strong enough for 176kgs 115hp ?

Thanks

Stu

[Moonlighter]

Stu, its not simply a matter of whether the transom is strong enough. Thats a part of it but .....

It is about a whole raft of things, including whether the extra weight will be able to be carried safety on the transom, whether the boat can handle the extra power safely. Stability at rest and underway, in sharp turns and in various sea conditions. Lots of things.

You are asking the surveyor to put his professional stamp of approval on something, that should it contribute to something going wrong, willl come back and bite him.

Here is a link to the Australian Standard :

http://54.206.50.69/wp-content/uploads/2014/04/New-Boat-Building-Standards-20101.pdf

Have a read of what it says about maximum power capacity, starts on page 16. Ypu can them take some actual measurements as required by the Standard and do the calculations yourself. And remember, even using that formula, it is them subject to successful completion of the on-water test detailed on page 49.

Your boat being a panga style with relatively narrow beam may make for an interesting case study of the application of the formula in the standard and the test.

That might give you a fair idea of whether there is any chance of the surveyor being able to endorse a increase to 115hp on your boat.

[Chimo]

Stu

Have you considered trading your motor on an Evinrude 90 HO which has the V4 same as the 115 block?

Where are you by the way?

Cheers
Chimo

[stuozfish]

Stu
Have you considered trading your motor on an Evinrude 90 HO which has the V4 same as the 115 block?
Where are you by the way?
Cheers
Chimo

No I haven't and to be honest, I am totally against Evinrude and ETEC's now. I've had lot's of issues !
Airlie Beach, Qld

[lethal098]

Good luck getting a surveyor to recomply the max HP,

Your only chance would be talking to the boat builder and see if they would rerate the Hull.

I had the same issue years ago with Savage, and they upgraded the hull HP as the newer model with no changes had the higher HP rating.

[fishingrod]

Check out this thread from a few years back re UB670 with a F115 Yammy :
http://www.ausfish.com.au/vforum/showthread.php/158496-Max-HP-6-7-southwind-longboat

It doesn't really answer your question about the ability to get the hull re-rated, as to my knowledge it was not done on this boat.
The hull did about 900 hours with the F115 fitted and no problems with the transom. And it got treated pretty roughly.

[stuozfish]

Thanks guys
I think I am now leaning towards a Honda 100hp 4-str - the BF100 with VTEC. It will save me the marine survey cost (and risk of survey cost with no better outcome) at $500. The BF100 is a newer model over the Yammie F100 so i assume later technology for fuel econ and power etc. They include a 7 year warranty, over 4 years for the yammie. I've also been told having a 115hp on UB670 makes it overpowered and can then require trim tabs and other things to help control prop torque etc. This appears to be evident by comments in the other post mentioned by fishingrod. Hopefully i'll get 30 knots out of a 100hp with 2-3 ppl and some gear ! cheers.

[ozynorts]

Have you thought about the new Mercury engines? The 115 4 stroke should be under your max transom weight. They also offer a Pro XS model in the 115.

[Noelm]

But, he is still stuck with a 115 HP motor on a 100HP max rated transom, regardless of brand.

[Chris Tucker]

$500 is cheap for that service. I get a couple of phone calls a week about this problem and the majority decide it is too hard, risky or expensive. It is acceptable to use the ISO standard to determine power which has exactly the same equations and test as as1799 but allows you to over-ride the calculated power by doing the test.

There are 3 basic steps to the process.

Step 1. Is the structure up to the extra weight. Most are but as the surveyor becomes liable they're going to want to do some calcs.

Step 2. Will the extra weight have stability or payload issues. Calcs and sometimes a physical test.

Step 3. Finally the practical test which involves doing a full speed turn within a radius related to the max speed of the boat.

The problem is you're not just up for the surveyors fees but you actually have to bolt the desired engine to the back to do the test and if you fail you're stuck with an engine you can't use. This is the deal breaker for most people.

[Ocean_Spirit]

What issues are you having with your 90 ETEC? That particular engine is near bulletproof. If repowering, assume you have been over your fuel system, etc. Less weight on the back end of that hull the better. To be frank, you will struggle with the physical tests on that hull if required. They weren't ever built for speed. Have spent a bit of time in them in Fiji.

Just extend the hull like a few of the 760's getting around on Sydney Harbour.!

[myusernam]

chip the compliance plate off and throw it away. If it was me i would reregister it as a generic longboat (probably switch insurance companies at same time) there are many iterations of these hulls around by many different builders.
I have a v4 115hp evinrude on mine (same hull but imported). its fine. in the us a popular eng choice is the 140 suzi. Gavin goodwin uses up to 150hp (he modifies stern but he used to put larger hp on same hull before he changed mould)
Many southwinds getting around with bigger hp. id say thats why you have been blowing up etec. working too hard. willow on here has one with 115 2 stroke yam? ex yam dealer in whitsundays had one with 140hp 2 stroke.
Mine is getting old and i want to change out and go bigger, but i will add some stern boyancy if i do. certainly can handle a lighter 115. id look at the merc 115xp with command thrust.

[Noelm]

I don't think he mentioned "blowing up" his current motor...that said, if it is propped correctly, then it has adequate HP and the motor will not be over stressed.

[fishingrod]

.... there are many iterations of these hulls around by many different builders.
I have a v4 115hp evinrude on mine (same hull but imported). its fine. in the us a popular eng choice is the 140 suzi. Gavin goodwin uses up to 150hp (he modifies stern but he used to put larger hp on same hull before he changed mould)
Many southwinds getting around with bigger hp. id say thats why you have been blowing up etec. working too hard. willow on here has one with 115 2 stroke yam? ex yam dealer in whitsundays had one with 140hp 2 stroke.
Mine is getting old and i want to change out and go bigger, but i will add some stern boyancy if i do. certainly can handle a lighter 115. id look at the merc 115xp with command thrust.


Just extend the hull like a few of the 760's getting around on Sydney Harbour.

Interesting comments.
The 670 Rescue Boat in the link I posted earlier was a genuine Southwind that was an ex Sydney Olympic Games support vessel. Originally fitted with a carby 80hp 4/ Yammy.

After being sold by the Rescue group, a marina operator took it over for use as a workboat (not in survey). They added some extra waterlength to the stern of the hull, in turn providing extra bouyancy.
They fitted a 135 Optimax, then after that upgraded to a 150hp Verado. I'm not sure how well it went. And I don't know if they got the hull "re-rated" in the process.

[ozynorts]

But, he is still stuck with a 115 HP motor on a 100HP max rated transom, regardless of brand.
Hmm perhaps I should have checked the OP again. I am not sure why I missed that....
The same brand in the 100hp is the same block so might be a good option. The 100 hp Honda would be a good pick as well.

[up the creek]

dont risk it bro if you cant afford to not be insured cos even if they say after survey your covered and happy to take your insur money at the end of the day they may use that against you in court if sum1 gets hurt in an accident and at the end of the day if your 90hp has made you happy all this time why wont a new 100hp do the job but hey why have insur if you dont know 100pc if your covered no matter what the sharks say id play safe but if you want extra ponies then i would do it if your boat transom is able to handle alloted weight and as long as it can handle twisting force of bigger outboard but id play it safe reccomended hp isnt just an insurance issue its safety and if you want more hp get a bigger boat that reccomends it and your insurance should pay.. hope this helps..

[Chimo]

I still say stick a 90 HO Etec on it and get an extra well built motor. Time to get beyond prejudice.