Evinrude E-Tec Foot Prints

[Willbrooksy]

Does anybody know if the larger evinrudes have the same foot prints (i.e. bolt holes through the transom)

Im thinking 115 > 300 hp range

im planning an engine upgrade on my 5.2m RIB

[Downhilldai]

Narwhal 520? Rated to 80hp? Are you thinking of an etec 75?

[Willbrooksy]

No...Im think evinrude 115+ with strenghting brackets

[Downhilldai]

In that case, I'd recommend you think again.

[Willbrooksy]

thats not the attitude i was expecting !!! When someone said they were going to build a boat made of rubber i bet people told him to think again and im going on the same principle !!!!

I have tested it out interms of extra weight and the difference off my current engine and a 300hp etec is 80ish KG so i stuck my 100kg mate on the transom and went for a burn and the boat handled exactly the same if not marginally better.

I spoke to 1 of the nav archs at work about strenghting the transom and said its rated to 90hp and he said the same as you but i created the attached diagram and he eventually said it could work and work especially well if we got the angles and tesnion right (thats his job lol)

But, does anyone know if the foot prints are the same ?

[chewy]

What do your insurance say?
Your putting a bottle screw in to strengthn the transom, how do you know what the right tension is?
The boat may have rode ok with the extra weight but imagine the force when you land off a wave.

I was the same with my SR4 could get hold of a cheap 70hp or 75hp but was advised against it, went for a 55hp in the end.

The Max hp is their for a reason. The bottle screw will look crap and will effect the resale value of the boat.

Should go like stink though!

[JSP]

If the lad wants to do it and thinks he can achieve I say good luck to ya. Just be safe!!

[chewy]

Originally Posted by JSP

If the lad wants to do it and thinks he can achieve I say good luck to ya. Just be safe!!

Says he with a 115hp hanging off an SR5.4

[JSP]

Originally Posted by chewy

Says he with a 115hp hanging off an SR5.4

ahh but I didn't put it there

[Downhilldai]

Originally Posted by Willbrooksy

the difference off my current engine and a 300hp etec is 80ish KG

Am I right in saying you have a 1998 75 Mariner (according to your profile) which you believe is 80kg lighter than a 300 etec?

[Rogue Wave]

What company is it you build RIBS for

[Downhilldai]

Originally Posted by Rogue Wave

What company is it you build RIBS for

[Willbrooksy]

dont plan to ever sell the boat, and if i do it will be sold without the engine anyway espcially if it does have a nice shiny new evinrude on lol - it will be worth more than the boat !!!

Havnt asked insurance but i presume it wont be too extreme - am I way wrong ? By the time this project gets completed i will have my advanced powerboat certificate + Certificate of competence which i imagine should counter the system ?

I had wondered about the wave issue and spoke to my personal nav arch and he said that if I do commit to it and buy the engine, in exchange for a spin when its done he would design brackets proffesionally on CAD but he deemed it a small issue with the right fabs. He reconed similar fabs on the inside or maybe solid 2" Stainless Pipeing all welded then its completely solid- No play! But as he said, for that to be efficient we need to get the measurements and angles spot on !!! He went on about forces and there directions i.e. the transom will hopefully only have the engine weight on it, all the forward backward forces go through mainly the deck !
I also wondered about creating a floating transom like some of the Atlantic Pacific boats do, like a chunky a frame with built in transom but that will move the weight of the engine further back and leverage and moments etc may not fun lol

By tension, I meant that theres no play between the bottle screw and bracket on deck + transom i.e. I throttle up and the engine pushes the transom then that directly transferred to the brackets then finally thru the bottle screw and into the deck !

[Rogue Wave]

I see

Originally Posted by Rogue Wave

What company is it you build RIBS for

[PeterM]

A word of warning about insurance. I recently was involved with a boat with a 90 Suz on it - the boat sank (fully - with 3 adults & 2 kids on board ! ) - the insurers despite knowing the make of both boat & engine and having taken the premium for 2 years declined to pay out. The boat was rated to a max weight of about a 50 -2stroke . So with hefty four stroke Suz on it - it got swamped.

Just be very carefull - but good luck !

[Willbrooksy]

Originally Posted by JSP

If the lad wants to do it and thinks he can achieve I say good luck to ya. Just be safe!!

Thats the attitude I like!!!


About the Company....I'd prefer not to disclose the company on here as I know this is a wild + crazy plan and DONT WANT MY PLAN TO BE CONNECTED TO THE COMPANY IN ANYWAY. But I will say that the company is a very respected, commercial boat building company with customers worldwide !

[Downhilldai]

Originally Posted by Downhilldai

Am I right in saying you have a 1998 75 Mariner (according to your profile) which you believe is 80kg lighter than a 300 etec?

?

[Downhilldai]

Originally Posted by Willbrooksy

... all the forward backward forces go through mainly the deck !

Does your Narwhal still have the original moulded GRP deck?

[Rogue Wave]

Originally Posted by Willbrooksy

About the Company....I'd prefer not to disclose the company on here as I know this is a wild + crazy plan and DONT WANT MY PLAN TO BE CONNECTED TO THE COMPANY IN ANYWAY. But I will say that the company is a very respected, commercial boat building company with customers worldwide !

Ahh must be MST, excellent boats

[Willbrooksy]

Originally Posted by Downhilldai

Does your Narwhal still have the original moulded GRP deck?

Yep