Yanmar compression release question
Donald H. Palmer
Rob Peterson wrote:
>
> MY dad's new yanmar 3 cylinder, 24HP diesel he's installing in his
> boat has individual compression release levers. It has no means to
> hand crank the engine for manual start and the engine manual says use
> the fuel cut off to shut down the engine. So, what the heck are the
> compression releases for?
> Any clues appreciated.
They would be used to help start the engine by hand. You would engage
the
compression levers on all cylinders, then you can get the engine
spinning
by hand, and then quickly dis-engage the compression release levers.
Donald Palmer
M/V 'The Energizer'
Albin 25' w/ 36hp Volvo
Cape Coral, Fl.
jack chalais
Actually, I would suspect that without any provision for hand cranking
the engine, the releases are for reducing the compression so the engine
can start spinning with a low battery. Then you can kick them in one at
a time to start. Maybe??
I have the same thing on my Yanmar D27 outboard, however this one has
the ability to hand start........ so they say.
-- Jack
jcha...@ns.net KD6UOT WAO9946
SV Hind Sight Doc# 691808 San Francisco, Ca.
"Here we go again.
Change lightbulb....rewire boat"
Rob Peterson
Sean Holland
The compression release make it much easier to turn the engine when
aligning it properly to adjust the valves, and I frequently use the
compression release prior to starting the engine, as it allows the
battery to spin the engine both easier and faster, which allows quicker
starts. This is a good choice when the battery is low.
Good Sailing,
73, Sean
--
Sean F. Holland
S/V Spindrift NP2AU
au...@lafn.org
Randy Zimmerman
In article <5amtjq$p...@newsfep3.sprintmail.com>, robpe...@sprintmail.com
says...
>
>MY dad's new yanmar 3 cylinder, 24HP diesel he's installing in his
>boat has individual compression release levers.
>
end of the camshaft. Under the cover was facility to connect a standard
crank. I have made up a crank and have used it in timing and adjusting
however I have not tried to start the engine. I was told by a serviceman that
it likely would be possible with two cylinders decompressed at first. I have
started this engine using the decompression levers when my battery was low.
It worked thus saving me from a lot of grunting with plan "B"
Access to this point is difficult because the alternator belt is in
the way on my engine.
Jere Lull
> MY dad's new yanmar 3 cylinder, 24HP diesel he's installing in his
> hand crank the engine for manual start and the engine manual says use
> the fuel cut off to shut down the engine. So, what the heck are the
> compression releases for?
They're for starting in marginal conditions. Flip off all three and you
loosen up the engine oil. Leave one down and you can start one cylindar
on (about) 1/3rd the battery requirements. Once one is firing, the
others can be pushed back down and all will fire.
We've got the 2gm20f and haven't had need to use the releases, though we
almost used them one 30-degree (F) day.
BTW, the new 3GMs should put out more like 27 HP at max 1-hour rating.
Watch the prop match carefully: these engines put out more than even
experienced yards are expecting. You should be able to attain 3400 or
3600 maximum. If you can hit more than that, increase the pitch or
diameter. When we repowered, Yanmar and the prop manufacturer
recommended a 14x12x2. We wound up with a 16x14x2 before it worked
right. Top speed increased from less than 6 knots to 7.3 knots.
Also would recommend a feathering and adjustable prop if you have a
choice. Sorry we didn't do that when we had the choice and were paying
the big bucks.
--
Jere Lull
Xan-a-Deux
'73 Tanzer 28 #4
out of Georgetown, MD
See how Xan-a-Deux looks at http://www.castle.net/~jerelull/X-Main.html
Mark A. Segraves
Rob Peterson wrote:
>
> MY dad's new yanmar 3 cylinder, 24HP diesel he's installing in his
> boat has individual compression release levers. It has no means to
> hand crank the engine for manual start and the engine manual says use
> the fuel cut off to shut down the engine. So, what the heck are the
> compression releases for?
I have also wondered why the compression release levers of the
Yanmar 3 cylinder diesel were not interconnected. Is there
a consensus here that it is OK to return compression to the
cylinders one at a time while starting - either with weak battery
or hand crank? The way that the levers are positioned, it would
not be easy to turn them all on at once.
Mark Segraves
Thomas 35 - Allegria
Evanston, IL
Sean Holland
In a previous article, m-seg...@nwu.edu ("Mark A. Segraves") says: > >
>I have also wondered why the compression release levers of the >Yanmar 3
>cylinder diesel were not interconnected.
Interesting how newer is not always better. Our Yanmar came with a bar
connecting all three compression release levers, as well as a fitting for
installing the control cable to release compression. Works great, and
can be used from the cabin rather than having access via the engine room.
Like that Yanmar better every year.
Good Sailing
73, Sean
--
Sean Holland
NP2AU
S/V Spindrift
make...@gmail.com
> Rob Peterson wrote:
> >
> > MY dad's new yanmar 3 cylinder, 24HP diesel he's installing in his
> > boat has individual compression release levers. It has no means to
> > hand crank the engine for manual start and the engine manual says use
> > the fuel cut off to shut down the engine. So, what the heck are the
> > compression releases for?
> > Any clues appreciated.
>
> the
> compression levers on all cylinders, then you can get the engine
> spinning
> by hand, and then quickly dis-engage the compression release levers.
>
> Donald Palmer
> M/V 'The Energizer'
> Albin 25' w/ 36hp Volvo
> Cape Coral, Fl.
Thanks,
Marc Auslander
the engine while I loosen the nuts at the injectors until fuels drips
and then close them.