Broken Yanmars - Page 2

crazyhorse · 31 December 2002, 11:35

Well Alan,

Thanks for being the bearer of bad news,Were all knackerd.

Crazyhorse

Manos · 31 December 2002, 13:03

I'm not an engineer but when I had boats with outdrives (and problems TO MANY TO MENTION!!) a VOLVO enginer told me more or less what Alan sais.
I have changed now to outboards (and smaller boats) and on the sailing cat (38 ft - 10 berth) I have 2 x mini VOLVOS 35 bhp each (under the aft beds) and as you would expect on shafts -take a bit more space than the leg but less moving parts.
Having had the experiences I had with the outdrives in the past I never had them on a boat I owned again. Now would only go for shafts (you need more space of course but not as many probs-is this correct or am I wrong??).
In short I believe that at sea the less complicate equipment one has on his boat the better it is.
I hope you all agree with that

crazyhorse · 31 December 2002, 13:23

Manos,your right with the less complicated the better.

But I got some work to do based on Alans post, as I looked long and hard at this baby and whent full circle.

I will come back to you with the imfo.

Crazyhorse

Manos · 31 December 2002, 13:25

Looking forward to it. This Thread has been an eye opener for me. Cheers

Garygee · 31 December 2002, 22:21

Hi Dirk

The engine is the 4 cyl, 240HP Yanmar.

This may help if they use the same mount on the 4 & 6 cyl engies as the engine will be lighter (I hope)

Regards Gary

crazyhorse · 01 January 2003, 13:56

All the best to everybody and your familys for New yr.

On with the buisness.Alan I am interested in your recomendations as far as the decisions re V drives and Jets as I am of the opinion that even though some combinations are unreliable, Outdrive/inboard are still are the most practical and efficient propulsion/economic/for there weight and size.
I am of the belief that ribs over 33 ft suffer from the deminishing returns syndrome,Big time and that aprox 33 ft is the overall size that Ribs will top out at this size and associated weights in the market place.
As this is there most efficient size for space and room and speed.

I am of the opinion that Z drives and Jets are very limited for Ribs up to that size of boat.I am aware of there specilised application benefits but I am looking at it for general use,space,economy and budget and speed.

Your thoughts and reasons will be most interesting on this subject and appreciated?

pint a lbs

All the best Crazyhorse

Julian · 06 January 2003, 14:27

Afternoon All

I have to say that we have been using Yanmar engines for the last 5 years and the engines have never dropped a beat. They are great engines and if they are installed properly with the heavy duty engine mounts as scorpion use you should not have any problems. There are problems with the drives but we all know about them and there's not much we can do.

I would reccomend Yanmars to anyone.

Julian

crazyhorse · 06 January 2003, 22:30

Julian thanks for your reply ,how many hours have you done using the same engine and what drive have you got.Do you no the weight of your boat.

Cheers Crazyhorse

Julian · 07 January 2003, 09:23

Hi Crazyhorse

We have the Yanmar 300 with the Bravo 3 leg with a shower cap fitted. Our current engine has done 490 hours so far and is fine. We blew our first gear box up after 80 hours of use. We had the leg re built using stronger parts and so far it has not let us down.

We spent a lot of money of extra beefy engine mounts and shocks that prevent the engine from taking too much abuse. Its not cheep but well worth it in the long run. Not sure of the exact boat weight but with fuel it must be 2.5 tons or so.

our last boat had twin 300 yanmars and they were fine to. They had done about 300 hours when we sold the boat. I think it depends on how you drive the boat. If you drive flat out in all kinds of sea Ie Racing then things will break. Best thing to do is not race, its too expensive.

Julian

crazyhorse · 07 January 2003, 11:22

Thanks julian,

It seems the engines are good but its just the legs that arnt.I think if you want longevity then its a Yanmar with a bravo 2 that seem s the way forward.I have a kad 300/dpg and will let you know how that seems to be.Its uknown at this stage so we will see.At least people that read these forums can get a feel for what is working and what doesnt in the hope they learn bye our mistakes.

All the best Crazyhorse

Daniel · 08 January 2003, 00:34

Quote:

Originally posted by Alan Priddy
Of course I would have to fit a bloody big self righting bag to turn it over when it broached in a big following sea and lost drive !

Alan - are you saying this is a pitfall of jet drives (i know very little about them, and nothing about their characteristics)?

If so surely this is somewhat of a problem for the boys re-tracing you're tracks accross the atlantic?

Julian...

What boat did you have twin 300's fitted into? A RIB?

Daniel

Alan Priddy · 08 January 2003, 08:25

The problem with a jet drive in BIG SEAS is the wave coming from behind tends to hit the boat a mid ships and lifts the transom out of the water. The boat is already running down hill like a runaway train only to find out it has no drive, no steering and is at the mercy of the wave pattern when it gets to the bottom. This is when the boat is liable to broach. It is not for me to say if "Team Youth" will have a problem, depends on how big the Atlantic seas are. Alan P

Julian · 08 January 2003, 09:12

Morning Daniel

Yes it was a Rib. It was a scorpion 9.5mtr with twin 300 yanmars driven through Bravo 1 drives. It was a very fast boat but not practical with that much weight in the back and every time you had a service done they had to crane the engines out to get at them as there was no room.

Ended up being very expensive but was good fun for a while.

Julian

crazyhorse · 08 January 2003, 15:36

I also believe that jet drives are developed for specielist applications EG people in the water rescue situations,Customs dont want to wave , at a drug runners who are using a jet boats and then watch them cross a shallow piece of water and be home before the customs vessel can catch the Damm skallywags.
Beaching a boat on a navy ship etc etc and so on.

They require approx 30% more power and fuel for the same at the prop,as a outdrive engine combination.

Im real interested weather the rnli have adopted them for there rescue boats as they have been tested but as far as Im aware aint been taken on?, for the same reasons that Allan has said.

Too skitty in real bad weather, and loose to much power and weight and room in the boat,and with a Jet and box and engine cost for a single 300hp at the prop equivilent can be 15k just for the Jet? Then add the extras like an engine ?

Crazyhorse

Daniel · 08 January 2003, 15:42

Ummm.. strange, i posted a reply this morning which is not here. Crasyhorse your's is here twice! have you hijacket it???

Anyway, what it said was something like how nippy the twin 300 of julians must have been, how envious i was of that and also to itterate how, that like Alan i am not wishing to quesiton the 'team youth' attempt, infact i wish them all the luck in the world.

Anyway, the RNLI have a jet boat on the thames, mored at Chiswick pier, had quite a good look over it when i was moored there over the summer (with they permission!). Strangly it had a completly open transom too.

I've had a run-in with the customs Jet boat, out ran them for a while (pretended i dident see them of course

) but they caught up as i entered the harbour. The rest, as they say, will be told once beer is in flow!

Daniel

crazyhorse · 08 January 2003, 15:50

Sorry Daniel I havnt hijacked your post as I was reading it and your right it isnt here.JK can you get Danniels post back as I have responded to it and it has dissappered.

Im sure your second post Daniel ist the same as your current post?

Bemused Crazyhorse

crazyhorse · 08 January 2003, 16:00

I look forward to a beer Daniel for sure.The point Im making about jets is in open Sea conditions,

Im aware of the Thames Rnli boats.Im not being rude but these boats are designed for the Thames and not open sea conditions.

Looking forward to your tale of customes apprehension on the high seas?,

Daniel · 08 January 2003, 16:01

How on earth did you manage that? Are you in my house? ARRRGH.

Anyway, an interesting point is how we all (myself included) assume JK is like Big Brother - always watching, and when we say "JK can you make the tea" he will. In reality, of course, he is watching, and he does reply, very promptly! Mines white with two.

Daniel

Daniel · 08 January 2003, 16:04

The tale, infact, involves getting stoped THREE TIMES on seperate occasions. Two far more interesting than the other! And no, before you ask, i know nothing about white powder, beer or any other desirable product be it banned or more expensive than europe in the UK!

John Kennett · 08 January 2003, 17:03

Daniel

I don't know what happened to your lost message. It seems to have sunk without trace. I didn't even see it

Anyway, get away from that wretched computer and drink your tea before it gets cold.

John