Yanmar YSB12 Questions
Kyle Ewing
I just purchased a 1978 S2 9.2A with a Yanmar YSB12. I've seen very little
written on the engine, but expect reliable operation based on Yanmar's
reputation. What can I expect from this specific engine, good or bad?
What sort of crusing range/engine run time can I expect with 18 gallons of
fuel?
Thanks in advance.
Kyle Ewing
kew...@mindspring.com
Chicago, Illinois
jim slocomb
maintained many of them when I was in the biz. I don't remember any
problems with s2 factory installations. Fuel consumption should be around a
quart an hour at a comfortable rpm.
Jim Slocomb
M/V Sea Otter
Bryon Kass
with raw water cooling. I had an 8hp version of that horizontal
thumper in a launch I built (11') and it got 30mpg! At cruising speed
expect it to use about 3hrs per gallon. Those 18gallons will last
a season or more. The problems associated with old fuel will be
the worst problem. I ended up using no more than a 5 gal tank for
the small launches for that reason. The only problem I had was the
oil has to be heavy enough to take the heat. Installing an oil
pressure gauge is better than the idiot lights as well as a temp
gauge. Correct maintenance is the way to long engine life.
Bryon Kass
webmaster and
Custom Design
150 Mechanic St.
Foxboro, MA 02035
508-543-9068 or fax 508-543-5127, Foot yard 508-384-2415
in THE ENGINE ROOM http://home.ici.net/~cusdn
Craig Lippman
Hi Jim:
I have an 8.5 S2 with a Yanmar 13 (circa 1981) that is noisy and vibrates. The
motor mounts are NOT stock S2 (i.e. NOT Yanmar), and the exhaust is simply a
Velux
waterlock. I'm going to try to re-aligning the shaft next season. The current
motor mount raises the motor bracket 2 1/4" above the beam; is this enough
clearance for a Yanmar motor mount? Would changing the mount make a difference?
Your reply will be very much appreciated.
Thanks,
Craig Lippman
S/V Jeannie
jim slocomb
No 2 1/4" wont make it. The yanmar mounts are app. 4 1/2 to 5" from bottom
to middle of the post. Yanmar mounts are also position specific on the
engine and come in various "strengths" which are matched to the engine.
Getting proper mounts for the old engines may not be possible so you may
want to consider doing a "proper" job with availabler mounts.
The definition of "proper" has a huge array of variables but the philosophy
goes like this.
1. There is no such thing as too much surface area where the engine
stringers attach to the hull. A little glass cloth and epoxy formed over
cardboard to make lateral stringers fore and aft of the engine and trending
outboard from the longitudinals works wonders.
2. Structural integrity and weigh dampen vibration. When rebuilding engine
mounts I lke to glass in fillers of apitong because it won't rot and takes
lag bolts or hangar bolts well.
3. Remember that vertical engines vibrate sideways and horizontal engines
vibrate up and down so give them some room to move.
4. You can use any two of these three points of flex. The mounts, the
coupling and the stuffing box. I hate flexible couplings so I like
flexmounts and a flexible packing box. A rigid packing box too close to the
engine will couple a lot of vibration into the hull.
I'm talking too much :-) .........good luck
fineg...@gmail.com
http://sailingthanksdad.com/?q=Yanmar-YSB12
brucein...@nowhere.org
Yanmar I used to get about 2 hours per gallon of diesel. But I believe
that most users of the single cylinder model get from 2 to 3 hours per
gallon, in an auxiliary sail boat.
But estimating fuel used on a boat is difficult as the amount of fuel
burned by a diesel depends largely on how much power the engine has to
produce to maintain the RPM that you have set with the throttle.
Whether up wind or down wind, how dirty the bottom is, what RPM you
run the engine at, all effect the amount of fuel used.
--
Cheers,
Bruce