yanmar ym 2000 won't start

Jagmandave · Sep 26, 2006

Sounds like an injector stuck open to me, easy enough to check...........

garyd · Sep 26, 2006

I changed the fuel filter and o ring. I dont see any thing wrong with the fuel bowl, dont see any reason to change that? Blead the fuel system before the filter after the filter and at the pump in that order. I did not remove the muffler as the bolts are very rusty and I dont believe that there is a restriction in the exhaust. I removed the air cleaner but it is new and in good condition. The motor turns over white white/gray smoke pours out of the exhaust. It will not fire. I have an I T manual on the tractor and I have tried to remove the injectors, no luck they are stuck!! I removed the 2 nuts that hold the retainer down on top of the injectors and removed the fuel line to the injector but I could not budge them. Any more ideas guys no luck so far. Still looks like the head needs to come off to me. What other trouble shooting should be done first? Please elaborate. AS always thanks for the help.
Gary<><

California · Sep 27, 2006

Somebody who knows something please comment on this: It seems to me that cranking it with the injector retainers backed off a little should blast loose the injectors. I know cranking will free a cylinder head after its bolts are loosened. Can someone critique this method, without making the focus how little I know?

Also, if the vapor you see is white then it could be water in a cylinder. I strongly recommend you start any cranking with the compression release used, to blow out any water since it is uncompressible.

normde2001 · Sep 27, 2006

"It seems to me that cranking it with the injector retainers backed off a little should blast loose the injectors."

That should work, otherwise you will have to pull the head and have them removed by a machine shop. When you crank it over, make sure you have strong fuel output from pump. When you get them out, install them upside down in the "banjo" fitting and crank it over, looking for a good "cone" pattern of fuel spray.

1danny · Sep 27, 2006

garyd said:
I changed the fuel filter and o ring. I dont see any thing wrong with the fuel bowl, dont see any reason to change that? Blead the fuel system before the filter after the filter and at the pump in that order. I did not remove the muffler as the bolts are very rusty and I dont believe that there is a restriction in the exhaust. I removed the air cleaner but it is new and in good condition. The motor turns over white white/gray smoke pours out of the exhaust. It will not fire. I have an I T manual on the tractor and I have tried to remove the injectors, no luck they are stuck!! I removed the 2 nuts that hold the retainer down on top of the injectors and removed the fuel line to the injector but I could not budge them. Any more ideas guys no luck so far. Still looks like the head needs to come off to me. What other trouble shooting should be done first? Please elaborate. AS always thanks for the help.
Gary<><

Take an air hose and blow around the injector, then put a double nut on one of the studs and back the stud out. You should be able to get a wrench or vise grips on the injector, twist back and forth until it is loose.

Danny

elarson · Sep 27, 2006

California said:
Can someone critique this method, without making the focus how little I know?

I think you are right on the mark. As long as you don't loosen the fastener too much and give it a slide hammer effect, all you are doing is applying a force that the parts were designed to endure.
As much as I had hoped it was something external and simple, I have a funny feeling were talking about a broken piston ring or something. Maybe I'm missing something, but I don't know of much else that creates the excess blowby that was described.

normde2001 · Sep 27, 2006

If it were mine, I would find a way to get that muffler off. Plugged mufflers are highly suspect when getting excess blowby, (where else is the exhaust going to go), and low power.

greatrandini · Sep 27, 2006

Yea, did you have it outside in a thunderstorm? Could just be water in the exhaust. Norme has a good idea about getting that exhaust off. Byt the way some of those fuel bowls shink in time, they still look great but they shrink and no longer make a good seal.

garyd · Sep 29, 2006

I pulled the muffler off tonite difintly not a plugged muffler. Moved on to the injectors. Pulled the studs just like you said Danny. I got a 14" cresent wrench on the injector worked her back and forth, popped it right out. reinstalled the fuel line in the injector and cranked it over with no compession. The injector sprayed fuel out seemed to be atomized but I don't know about the prefect cone. The tip of the injector seems pretty carboned up to me. Move on to the rear injector which proved abit more challanging but it eventually come out. It too was very carboned up. I soaked all the nuts, bolts and injectors with liquid wrench over night, I have always used wd-40 I don't know but I think the liquid wrench might be better. I reinstalled the fuel line on the rear injector and cranked it over again. This time fuel sprayed from both injectors alternating but there was a distinctly different sound from rear cyclinder, more air? I reach over and stuck my finger in the injector ports and it seemed that there is less compression in the front cyclinder. Note to self watch out for High pressure fuel from injectors ouch!! How do you check compression? This doesn't look good!!!!
Injectors to the shop to be over hauled. Head off to see how bad it is. any advice or suggestions? looks like I will need alot of parts. I dont know I'm kind of bummed out. Thanks for the help TBN GUYS Lets fix this tractor!!!
Gary<><

1danny · Sep 29, 2006

garyd said:
I pulled the muffler off tonite difintly not a plugged muffler. Moved on to the injectors. Pulled the studs just like you said Danny. I got a 14" cresent wrench on the injector worked her back and forth, popped it right out. reinstalled the fuel line in the injector and cranked it over with no compession. The injector sprayed fuel out seemed to be atomized but I don't know about the prefect cone. The tip of the injector seems pretty carboned up to me. Move on to the rear injector which proved abit more challanging but it eventually come out. It too was very carboned up. I soaked all the nuts, bolts and injectors with liquid wrench over night, I have always used wd-40 I don't know but I think the liquid wrench might be better. I reinstalled the fuel line on the rear injector and cranked it over again. This time fuel sprayed from both injectors alternating but there was a distinctly different sound from rear cyclinder, more air? I reach over and stuck my finger in the injector ports and it seemed that there is less compression in the front cyclinder. Note to self watch out for High pressure fuel from injectors ouch!! How do you check compression? This doesn't look good!!!!
Injectors to the shop to be over hauled. Head off to see how bad it is. any advice or suggestions? looks like I will need alot of parts. I dont know I'm kind of bummed out. Thanks for the help TBN GUYS Lets fix this tractor!!!
Gary<><

Take the injectors to the diesel shop and tell them to check the spray pattern & the pressure, the pressure should be within 100#'s psi of specifications. If the spray pattern is not correct, replace the nozzles, don't try to clean them. The nozzles are about $ 35 ea.

Danny