Yanmar Turbo Diesels

tsunami · 12 September 2001, 11:05

Just wondering if anybody has any experience with the Yanmar Diesels around 250 - 300 hp. How do they compare to the Yamaha diesels for example? Price, performance etc...

MarkWildey · 12 September 2001, 16:39

I have had both, and can recommend both units for use in RIB's. The HydraDrive in the Yam is fantastic compared with the Yanmar gearbox.

Throttling up from 3200 ( 35 knots ) in the Yanmar gives a real sense of acceleration and 45-50knots soon comes up on the GPS.

Unfortunately the boat with the Yamaha in was much heaver ( 45kn max ) than the Yanmar boat so I cannot compare top speeds, but the Yamaha should give a good turn of speed, 40-45knots ?

The only issue with the Yanmar in the past has been the Bravo 3 leg, which couldn’t cope with the torque from the 300Hp engine. This has been corrected, so we believe (?) with the Bravo 3x leg, which is fitted, on my boat.

Regards

Mark

tsunami · 12 September 2001, 16:58

Hi Mark,
what boat have you got at the moment? I've had experience with both the 165 & 240hp Yamaha's and the gearboxes are fantastic. I've no experience with the Yanmar but have used the bravo legs on various Mercruiser engines! The thump of the gearbox as you put the engine into gear is quite annoying.
I've got a friend running the new Yamaha 250hp and he has burn't out 2 legs after a total of only 125 hrs!
What size and weight was the boat with the Yamaha?

MarkWildey · 12 September 2001, 18:49

The boat was a BWM 28 but what the weight was I have no idea. Paul Lemmer who built it said it was the heaviest boat they ever made and was built to go through anything.

It was a fantastic rough water boat and gave a really good dry ride and is now in Ireland somewhere?

Mark

Scubakid · 13 September 2001, 13:13

I had a 230Hp Yanmar and this was very good, the only problem I had was with the altenator belt wareing very quickly, Yanmar said this was because I did not use the boat often enough and so the pullies were rusting and so abrading the belt

tsunami · 13 September 2001, 14:51

Thanks for the info lads. I'm going to be at the Southampton boatshow over the weekend so I'll gather up all the info I can and make a decision then.

Alan Priddy · 13 September 2001, 16:24

If your mate has burnt out two Yamaha gearboxes in 125 hours he needs to have a good look at the installation because something is wrong with the boat. I run a Yamaha 240 in the Spirit of Cardiff which is 6.5 tonnes when fuelled and runs for 300 hours in between gear oil changes with no problems.
Alan P

tsunami · 13 September 2001, 17:01

Hi Alan,
the boat setup as far as he knows is fine as he has built very many the same as it. The boat they are fitted in is an 11m rib with twin yamahas, the boat weighs about 5.5 tonnes.
At present he is very happy with the yamaha engines and is fitting somewhere in the region of 30 units per year to various sizes of ribs!!
There was never a problem with the 240hp yamaha but the new engine that is giving the problem is apparently 250hp? at the leg. Maybe this extra horsepower is causing the problem??
You can actually see the paint on the top of the leg starting to blemish with the heat. Maybe this is a rogue leg as the other engine seems to be fine.

dave h · 13 September 2001, 19:05

Have friends with both setups. The yamaha is nice and responsive from low revs, but the drive can give a lot of problems if you don't use a really good oil and change it reguraly. Once they start to give problems there are no cheap fixes! The yanmar 300 is a lot more grunty once it is spinning and the 3x leg seems to have sorted the drive problems out. If you price around there is very little difference in cost.

Alan Priddy · 13 September 2001, 19:45

Hi Joe

This new engine is rated @250hp at full revs and the leg will take up to 260hp so this isn't the problem. The discolouring on the top of the drive is not an idication that he oil or leg is getting hot. If you have a look inside of the housing you will see that it is like brand new! I have tested this leg in extreme conditions for extended periods of time inbetreen oil changes with no problems at all. All things considered it has to be said that Yamaha have had their stern drive units out a lot longer than Yanmar who have had to fit the new leg due to a 100% failure rate. I have come across few problems with the Hydradrive unit and most of them have been in twin installations. Has the unit that gave the problem be run counter rotating or perhaps at speed the turbulance off of the leading drive is enough to create bad cooling to the following leg. If only 1 unit has given problems out of 30 sales perhaps it's "Murphy's Law" at play.

Are you going to Peter G's do at the end of the month? I am doing a slide show of the Arctic Atlantic expedition if you are.

See you? Alan P

batfalcon · 14 September 2001, 06:30

It would be nice for all of us, if you could post some photos from that expedition. If they are large and sharp enough, we could use them as wall paper on our monitors, or even print them as a mini collection for our offices.

Alan · 14 September 2001, 09:41

Joe,

You might want to have a chat with Brian Elliot, who as you probably know runs a Yanmar 300/ Bravo 3 dpx in Cyanide. I know that he has had to have some warranty work done on the leg after RB4 and also had a mod (as fitted to Hot Lemon) to improve cooling.

Not my place to say more, but I reckon there might still be concerns with the Dpx drive.

Alan

PS, Sorry Brian if I am talking out of turn!