Advice about Inboard engine

phildefer · 15 April 2005, 14:30

With some friends all divers, we would like to by a rib around 7,5 m. We maybe have find one with an inboard diesel Yanmar 240 cv.
Could you give me some advice ? Is it a good engine ? And what about the outdrive legs, spare part prices and customer service ?
What are the advantages Inboard versus Outbord, Does this kind of engine as a longer life than an outboard engine ?

Thank a lot (sorry for my English)

Phil

codprawn · 16 April 2005, 03:44

Yanmar are very good engines - they normally use mercury sterndrives which are pretty good but can cause problems on the bigger engines - about 300hp.

Diesel is VERY popular in the UK because at the moment we can use red diesel which is 3x cheaper than petrol here.

When the costs are about the same outboards tend to be more popular because they are so much lighter and take up less room - quite important if you want lots of divers in the boat.

phildefer · 16 April 2005, 09:05

Thank,

We aren't so lucky with red diesel, only professional fischer or farmer are allowed to use it.
Could you tell me if I can expect a longer lifespan (time life ?) and a cheaper maintenance with an inboard engine ?

Phil

Alan · 16 April 2005, 13:02

Longer lifespan? Maybe, Lower servicing costs than outboards? No, I think inboard servicing costs are generally higher. Outboards are much more accessible. Other thing to consider is that an inboard engine will take up a lot of room even in a 7.5m RIB. For Diving you want lots of room right?

The Yamaha 240hp/Hydradrive is well thought of. Alan Priddy went around the world powered by one.

phildefer · 16 April 2005, 18:52

Thank Alan,

I dont no why but I thought lifespan was beter (aroud twice in my mind) and servicing costs were higher for the first years but cheaper after 4 or 5 years.
am I wrong ?
For diving, we need area to put tanks, but they are in front of the console. Behind, we need area only to have a seat on the rib

Phil

Andy Gee · 17 April 2005, 14:56

My current Rib has 2 Yamaha 165hp inboards, every 50-70 hours I service both the engines and legs approx. costs for both units are;
Leg oil 2.2 ltrs per leg total cost £10.91
Washers and seals £1.30
Castrol Engine Oil £42.00
Filters (Fuel and oil) £60.00
So one engine costs £57.11 per service. You can string the service hours out to 100 hours if you want.
I generally do around 150-200 hours per year and probably spent around another £150 per year on small repairs and renewals i.e anodes etc.
When I had outboard I usually spent around £350 per year on servicing etc.
HTH
Andy

phildefer · 23 April 2005, 09:16

I've been reading the forum for a week, and I'm still asking my self : is a Yanmar 240 with Bravo 2 leg more reliable than an outboard engine ?

My english is perfect and it's sometime dificult to enderstand your meaning in all treads about trouble with Yanmar and outdrive

Thank again

Phil

Alan · 23 April 2005, 12:02

Phil,

Yanmar 300 with Bravo - buy/operate at your own risk. They do have a record of failure for whatever reason.

Yanmar 240 with Bravo. I don't believe the same level of problems have been reported but you need to do your own research and make your own judgement. If I were operating any large diesel / outdrive I would fit a drive shower (stainless steel thing that cools the leg by shooting water over it) as a safety precaution against the leg overheating.

Cheers,
Alan

phildefer · 23 April 2005, 12:48

Quote:

Originally Posted by Alan

Phil,

Yanmar 240 with Bravo. I don't believe the same level of problems have been reported but you need to do your own research and make your own judgement. If I were operating any large diesel / outdrive I would fit a drive shower (stainless steel thing that cools the leg by shooting water over it) as a safety precaution against the leg overheating.

Cheers,
Alan

Where does the water comes ? is there a pump or water is puching by the speed's boat ?
It's amazing, I can't anderstand why so much failure with rib. Many boat use outlegs and at high speed, a lot of them don't have much water than rib around their outleg !

Phil

simmons0 · 23 April 2005, 13:34

Shouldnt of thought you would need a drive shower with a 240hp diesel.
In my opinion, i wouldnt worry about drive showers at all untill you have the boat and engine, then you can look for the signs of the drive overheating.
Usually a white residue left onto of the drive where salt water has boiled away.
If you do get that, fit a drive shower, but i would think it very unlikely with a 240hp low reving diesel set up.

Powerboat · 24 April 2005, 16:27

I would have thought that for a dive RIB that single or twin 4 stroke outboard is the obvious way to go.

Inboards take up too much room on a dive boat especialy a small one like a 7.5 !

Best wishes,

Stuart