Yanmar 6LP STZE

Philip Hodson · 13 February 2019, 10:10

Can anyone tell me is a Yanmar 6 LP based on a Toyota 4.2 engine.

Phil

beamishken · 13 February 2019, 10:46

Yep it is toyota 1hd from landcruiser. Several diferances though pistons are yanmars own but rings bearings gaskets filters and many other bits are toyota

Philip Hodson · 14 February 2019, 10:22

Thanks Beamishken most helpful.

Phil.

Bushrider · 14 February 2019, 14:54

I have the same 6LP .
Can somebody advise where I can get a workshop manual ?
Thank you .

beamishken · 14 February 2019, 21:57

https://www.barrus.co.uk/divisions/m...ual-downloads/
Available to download free here

Bushrider · 15 February 2019, 07:32

Quote:

Originally Posted by beamishken

https://www.barrus.co.uk/divisions/m...ual-downloads/
Available to download free here

Much appreciated - thank you !

gtflash · 16 February 2019, 09:22

is that the same engine as a Yamaha ME420sti

beamishken · 16 February 2019, 13:05

Yamaha 420 is the toyota 1hd with the 12 valve head (a few yamnars used the 12v head too but not many) different marinising equipment used obviously. One key diferance is yamaha used their own piston rings instead of the toyota ones which makes building a 420sti way more expensive than a 6lp

M.Thornton · 16 February 2019, 15:47

Quote:

Originally Posted by Bushrider

Much appreciated - thank you !

Now then Jurgen,don't go tweaking that engine to make it faster than ours !!

Bushrider · 16 February 2019, 15:52

Mike- no need to tweak - it's already faster [emoji12][emoji16][emoji106]
50kn to beat [emoji6]

GuyC · 16 February 2019, 16:03

50 knots - that's faster than my 1HD engined Land Cruiser. I do get 5 miles to the litre though.

M.Thornton · 16 February 2019, 16:20

Quote:

Originally Posted by Bushrider

Mike- no need to tweak - it's already faster [emoji12][emoji16][emoji106]
50kn to beat [emoji6]

Just wait till we hoist the spinnaker

Bushrider · 16 February 2019, 16:22

Quote:

Originally Posted by M.Thornton

Just wait till we hoist the spinnaker

Hmm .. - that's not fair [emoji16][emoji23][emoji1787]

gtflash · 19 February 2019, 10:57

Quote:

Originally Posted by beamishken

Yamaha 420 is the toyota 1hd with the 12 valve head (a few yamnars used the 12v head too but not many) different marinising equipment used obviously. One key diferance is yamaha used their own piston rings instead of the toyota ones which makes building a 420sti way more expensive than a 6lp

Is there any performance gains to be had out the 12v Yamaha. I’m interested in a boat with one but it only does 30mph

beamishken · 19 February 2019, 11:29

I think the 240hp is getting close to the max, the 12v 1hd was 150 or 170hp in the landcruiser so its already up from stock. Iirc there was a HO version of the 422 at 275hp which had a larger intercooler and a few other mods but I'd imagine any gains would be quite costly to achieve.
Must be quite a heavy boat to only do 30mph? my 7.4m delta does 40kts with the same engine
does it have a problem or is it just underpowered?

gtflash · 19 February 2019, 16:49

It’s a windy 8800. Weight values are anywhere from 2.5t to 5t. They typically have twin ac211 v8 Pentas so underpowered. Lovely boat otherwise

beamishken · 19 February 2019, 19:32

I'd guess the 2.5t is single petrol light boat & 5t is twin diesel fully loaded? so at a guess the diesel with a medium fuel load etc should be a touch under 3t? it still seems very slow.
I owned a crownline 242 which tipped the scales at 3t empty of fuel etc and loaded for a 2 week holiday for 4 it still did 36kts with a 250hp mercruiser diesel which i doubt is much if any more powerfull than the yam. Unless the windy hull is very deep vee making it power hungry I'd be looking for a problem causing a power loss.
If the 30mph comes from manufacturers figures then ok thats what it is but if its from a test run then id suspect a running issue.

Ribgalway · 29 November 2024, 13:45

Not sure if you still have this. I have that engine in my 8.5m tornado rib. It does 32 knots but is very slow on acceleration. Have you ever played with the fuel pump for more power?

beamishken · 29 November 2024, 16:04

Quote:

Originally Posted by Ribgalway

Not sure if you still have this. I have that engine in my 8.5m tornado rib. It does 32 knots but is very slow on acceleration. Have you ever played with the fuel pump for more power?

You can increase the pump a little but you have to do it with an exhaust gas temperature probe installed, if you start overfueling & increase egt's too much you risk piston/valve meltdown
What drive do you have? & what is your max rpm at wot? The Yamaha's dont usually suffer turbo lag as much the yanmars do, could you be overpropped?

Ribgalway · 29 November 2024, 16:12

Ok thanks.
It’s the Yamaha hydra drive.
When you put down throttle, the lag is terrible. It takes definitely 15 seconds before you begin to feel noticeable acceleration, then when turbo kicks in it’s good. It’s the standard prop not sure of the pitch.