New Dive RIB Engine

[HelmGuy]

Hi all, I'm looking for some help and advice on a new outboard engine for our dive club RIB.

We have a 6.5m Humber Destroyer, currently with a 140hp Yamaha 2-Stroke which is about 15 years old. The engine runs well and we like the power we get from it. What we don't like is the noise, smell, reliability and mostly the fuel economy we get from it.

So we're looking for something new that will cut our fuel bills.

The small amount of research we've done some far has brought up options such as the Yamaha F150 4 stoke, Mariner 150 4-Stroke or a 2-Stroke Evinrude e-etc.

We're looking for something that will give us similar performance to what we're used to with improved fuel economy.

Any one have any input advice on any of the above enignes or indeed any others that might be suitable for us?

Mark

[willk]

The new Mercury/Mariner 150 looks good on paper.

A few of us on here have had trouble with Etec Engine Management Modules - at a grand to replace one - personally, I'd avoid...

[Razorbill RIBs]

Originally Posted by willk

The new Mercury/Mariner 150 looks good on paper.

A few of us on here have had trouble with Etec Engine Management Modules - at a grand to replace one - personally, I'd avoid...

As Willk says the new Merc looks great....funnily enough I was having a poke around with one yesterday (one of a pair of twins)..... The owner (commercial) was full of praise for them.....

For me (and poss because we live in a rural area) a good relationship with the local dealer would be a deciding factor..... that said, we now use 'Black Dog' in Looe wherever possible (post on here) who depsite the geographic seperation have always been a LOT more helpful /knowledgeable than some of our local (ish) dealers....

[Johnscubanut]

We run the yam 115 four stroke, great engine, good fuel consumption. Heard very good results about the Suzuki 140s fours also. Be aware all the fours are considerably heavier though!

[captnjack]

I have heard of several Yam F115s getting rusty oil pans which basically requires replacing the powerhead since the oil's ruined. Don't know about the others.

[Turbodiesel]

Originally Posted by captnjack

I have heard of several Yam F115s getting rusty oil pans which basically requires replacing the powerhead since the oil's ruined. Don't know about the others.

Funny that, i have a F100 Yam in at the min with a rusty sump full of water!

[Chris]

If you want the same performance that you get from your 2 stroke Yam then go with the E-tec. Make sure you get the 5 year warranty though and ensure you have good fuel filters / water seperators fitted.

I know Mollers and Willk had EMM issues but I would not let a couple if instances put me off. They are great engines and there are 141 people on here who have not reported EMM problems.

That's less than 2% emm failures

[CJL]

We re-powered with a Merc 150hp 4 stroke;

http://www.rib.net/forum/f16/re-powe...5-a-51202.html

[willk]

Originally Posted by Chris

I know Mollers and Willk had EMM issues but I would not let a couple if instances put me off. They are great engines and there are 141 people on here who have not reported EMM problems.

140. Pikey Dave lost one too. I lost both of mine.

I couldn't in all honesty recommend them to another based on two out of two failing. Maybe they were abused by the previous owner - I dunno. Nice engine to use, nippy and frugal. Not sure they're suited to a Dive Club unless the maintenance is up to scratch...

[Chris]

See your point, would not stop me from buying another though, which just goes to show how much fun they are !

[Miller]

How about an opti?

[HelmGuy]

Cheers guys. As we're used to a 2 stroke at the moment the Etec is something several memebers of our club would like to go for - so that's a definite option on the table.

Just need to make a decision between Evinrude 150 etc or Mariner 150 4 stroke.

Interesting talking to dealers but it's pretty obvious that they are recommending what they sell! ;-)

[Derfla]

Hi Chaps

I'm from the same club as HelmGuy.
I have a silly question

When talking of hours run for servicing does that include idling time or only when under load??

As a day out on the Rib will will be 8-10hrs but the engine is only really under load for maybe 2 hours.

Do the modern trip display/control computers monitor this.

Why I ask is the servicing intervals for the 2 engines that we are looking at are a large factor seeing as the 4 Strokes are typically 10, 50, 100hr service intervals
whereas the 2 stroke Etec is 300hrs and only a minor check up yearly.

many thanks

Fred

[Peter_C]

Originally Posted by Derfla

As a day out on the Rib will will be 8-10hrs but the engine is only really under load for maybe 2 hours.

That is an enormous amount of idle time. I personally wouldn't consider anything but a 4 stroke in that situation.

Just how many dives are you guys doing in a day? I would assume that is multiple trips with different people?

Originally Posted by Derfla

Do the modern trip display/control computers monitor this.

Easiest to put a simple hour meter in plain site somewhere, like the dash. Keep a "next service" sticker right near the hour meter.

Originally Posted by Derfla

Why I ask is the servicing intervals for the 2 engines that we are looking at are a large factor seeing as the 4 Strokes are typically 10, 50, 100hr service intervals
whereas the 2 stroke Etec is 300hrs and only a minor check up yearly.

Once broken in the outboard need appropriate servicing. The more hours consistently run, the less service it needs per hour. A motor that sits or is used little will need servicing at lower hours. IE: Let's say manufacturer recommends 50 hour oil changes. A boat used daily for hours every day that interval could be lengthened to 80 hours. Yet a boat that gets used less than 40 hours a year needs an oil change at least once a year so it may never even hit the recommended service interval.

On the other side how the motor is used also plays a part in it. One that is used at max power all the time, or slammed through the surf like a raced Zap Cat engine, would require more frequent oil changes in order to monitor its condition. Idling for hours on end is not good for an engine either, so more frequent oil changes should be performed. Engines prefer a steady, constant, light to medium load.

[Derfla]

[QUOTE=Peter_C;513792]That is an enormous amount of idle time. I personally wouldn't consider anything but a 4 stroke in that situation.

Just how many dives are you guys doing in a day? I would assume that is multiple trips with different people?

Typical Day is launch
Out to dive site (20-25min)
Potter around dropping off divers and collecting (1-3hrs)
back in for lunch (20-25min)
back out to a different site (15-20min)
Potter around dropping off divers and collecting (1-3hrs)
back in and retrieve (15-20min)

So as you can see just pottering around on barely over idle and idling is the vast majority of the day.


Easiest to put a simple hour meter in plain site somewhere, like the dash. Keep a "next service" sticker right near the hour meter.

I know fitting an hour counter is easy but by my very basic maths we'd be getting the first service on a 4 stroke engine after a single weekend away.
Does that sound right???

Then again after a further 4 weekends away. (could be as little as a month after first getting the engine)

This to me seems excessive.

Rgds

Fred

[captnjack]

Originally Posted by Derfla

I know fitting an hour counter is easy but by my very basic maths we'd be getting the first service on a 4 stroke engine after a single weekend away.
Does that sound right???

Then again after a further 4 weekends away. (could be as little as a month after first getting the engine)

This to me seems excessive.

Rgds

Fred

The first 10hr service is a "break in" service. You probably want to run up 10hrs of use without customers/divers/guests. Its a time when you need to be varying the engine RPMs and not running under full load.

After that most 4 strokes have a 100 hour service interval. My RIB is a dive boat and I never hit 100 hrs in a year. Like you its 30mins out to a dive site then tied up or anchored for 2 hrs then 30mins to the next dive site. The "puttering around" for ~2 hrs is going to foul up any 2 stroke plugs big time. And yes it drives up the oil changes on a 4 stroke. That's just the way it is. Idling is not really "easy" on an engine. Shutting down the engine while divers are in the water is really your best solution since you'd be pretty foolish to try extending the service interval because you were only idling for 50+% of your engine hours.

[Turbodiesel]

The Merc 150 has a service monitor as well so it looks at load factors etc and will let you know if the oil needs changing earlier or not. But its a 20hr service or 3 months then once a year or every 100 which ever comes first. The service costs are probably more on the 4 stroke over a ETEC but your not poring in very expensive 2 stroke oil in all the time and at £40.00 for 4ltrs it will soon add up!.

[Johnscubanut]

We usually shut the engine down as soon as we have hooked the wreck, quick release hitch onto the bouy & wait for 20-30 mins before releasing & then patrol downstream awaiting them to surface.
Drift dives you will be doing varying speeds anyway?
I agree, the cost 2 stroke oil that you won't be using will soon save you money & you won't be fouling your plugs up!!! Cheers-John

[Johnscubanut]

BTW we have an hour meter fitted & service now every 100 hrs.

[HelmGuy]

Thanks for all your input guys. The dive club's commitee decided on a new 150hp Evinrude 2-stroke in the end so looking forward to getting it installed and seeing what it can do.

We have our current 2-stroke up for sell on ebay: Yamaha 140 V4 Outboard Engine Complete 1989 | eBay