YANMAR YSM12 Owners?
David Dawe
I have a diesel YSM12,1980,hard to start,new tank,new filters,no air in
lines,clean fuel to engine,what should I check or replace next? Any help
appreciated.
Bruce Tadd
On 22 Jun 1996 10:59:29 GMT, obb...@InfoNET.st-johns.nf.ca
(David Dawe) wrote:
:I have a diesel YSM12,1980,hard to start,new tank,new filters,no air in
:lines,clean fuel to engine,what should I check or replace next? Any help
:appreciated.
FWIW...assuming "fuel to engine" means clean fuel thru injectors
to cylinder:
1) Air Filter (all our Yanmars need is fuel and air to run)
2) Battery (you may be on the back end of your starting
battery's life, and just a few rpm's low on start may affect
starting time)
After that you get into the interesting like "compression",
"injectors" and all that messy stuff.
g'luck
Bruce Tadd
bt...@gnn.com
bt...@juno.com
http://members.gnn.com/btadd/stand.htm
Graham Moss
> (David Dawe) wrote:
>
> :I have a diesel YSM12,1980,hard to start,new tank,new filters,no air in
> :lines,clean fuel to engine,what should I check or replace next? Any help
> :appreciated.
>
I used to have one of these engines - If I remember right, the fuel does not
recycle to the tank - It just has a direct connection from the engine fuel
pump to the injector. Provided you have no air in this line (checked by just
cracking the fuel line at the injector until no bubbles form) then you have
fuel and you have air so the engine should run.
However, these engines are sensitive to temperature and I notice you are in
Newfoundland. Here in Lake Ontario, we had slow starting in early May, and
sometimes had to use the decompressor to allow the engine to spin fast so as
to slosh some oil up into the rings and thus get better compression. After
doing this, try rotating the engine using the hand crank against compression
- you should not be able to turn the engine over. (By the way, we always
started our engine by hand (or with a weak battery) after a long race by
using the decompressor. If you have low compression, a set of rings will be
needed. Only other thing, might be a worn or plugged injector.
Good Luck.
Graham & Gerry Moss
Windjammer Sails, Box 23004 Amherstview PO Kingston Ont.
Canada K0H 1G0. (613) 389-4349 FAX (613) 389-4762
"Everything for sailing - At a good price!"
MAIL WEB SITE
wind...@fox.nstn.ca http://fox.nstn.ca/~windjamm/
Marc Auslander
I'm not an expert but I would think you should first verify that the
battery is cranking the engine quickly enough. Assuming it is, the
problem is either compression or the fuel system. If you've never
serviced the injectors, that might be the problem. You'd need to pull
them anyway the check the compression.
--
Marc Auslander <ma...@watson.ibm.com> 914 945-4346 (Tieline 862 Fax x4426)
cusdn
They have a hand crank feature. If you can crank the engine without
releasing the compression then the rings are bad. If you almost
break your arm as it bounces you back then the fuel pump is not working.
First see if when it cranks does any white smoke come from the exhaust
on full compression. If not the fuel lift pump or the injector pump is
bad. Some of those engines had electric fuel pumps which should click
when activated. If the pump doesn't cause fuel to piss out when the
ignition is on and you open the prime port on the inj pump then see why
the pump is NG and replace. If its mechanical and you can pump fuel
to the inj pump and it primes easily and when cranked sprays fuel out then
the next step is the inj pump. If the fuel is not spraying out of the
injector high pressure line when it cranks then the injector pump
plunger is stuck. The plunger if let sit too long in old fuel
will stick in. Remove the inj line and fuel supply then the pump. Watch
and make sure the segment control is visible for reassembly (small fork).
Try on the bench pushing the spring loaded plunger. If it doesn't move
then it need to be worked loose. See if the plunger control rod rotates
through its full travel (about 90 deg) if it will not move then try
a little harder making sure you don't bed it. If it starts to move and
the spring expands then you may have it. Try moving the plunger again
until everything move easily. You could remove the valve that sits
below the high pressure line and add some WD 40. Once moving reassemble
the pump to the engine making sure the segment control gets the segment
pin. If the engine now pumps fuel to the injector and still won't run
the injector is frozen or the injector pump is NG. Try removing the
injector and have it tested. The pressure should be around 2500 psi
when it sprays a conical pattern (dangerous) and hold near that pressure
without dripping. I may have an inj pump and injector insert for that
engine. Good luck.
Bryon Kass
Custom Design in
THE ENGINE ROOM at http://www.ici.net/customers/cusdn
Gary Mace
David Dawe wrote:
>
> I have a diesel YSM12,1980,hard to start,new tank,new filters,no air in
> lines,clean fuel to engine,what should I check or replace next? Any help
> appreciated.
I have a YANMAR YSM12 which was hard to start. After getting the
injector replaced it cranks fine.
Good Luck
Gary
--
Bistro Marketing, Inc. | GJ's MAGIC-DUST[TM]
PO Box 1720 | Gourmet Spices & Marinades
Cary, NC 27512-1720 |Email: bis...@ix.netcom.com
Phone 919-773-9100 / FAX 919-773-9111 |http://www.netcom.com/~bistro
OldportMar
pattern. This will require "pop testing" on a bench to check. This is an
old engine at this point and may need to have the injection pump "timed" a
procedure done by shimming the pump. Next would be a compression check,
if compression is low then starting is very hard.
Good Luck, Ron Ackman/Oldport Marine/East coast Yanmar dealer 401 847
9109