Yanmar 1500D Engine Runs Full Speed

[gweishaar]

The Yanmar 1500D is back together with a new clutch. After several trials of air bleeding it started up. Now another problem, the diesel engine runs at full speed. I have tried moving the throttle. Throttle forward is supposed to be slower - back is faster but there is little speed change if any where ever the throttle is set. When started the tach ramps up quickly and reads over 3000 rpm. Thankfully I read some of the posts the other night and recalled that the only way way to stop a diesel is to cut off the fuel. I closed the fuel shut off valve and the engine shut down. I started it again and still the engine ran up to full speed again. I tried to control the speed by the closing and opening the fuel shut off valve but it either ran full speed or died as I tried to maintain a set speed.
Even though the linkage is not binding, I removed the throttle linkage at the connection on the arm where the shaft goes into the engine. Still the same when operating the arm without the throttle linkage or lever. When operating the arm by hand without the linkage there seems to be resistance by a spring (concealed). Maybe something is frozen inside.

I am afraid to run this thing at such a high rpm. I don't want to have it fly apart. I am wondering if I will ever get some use out of it. Any ideas?
http://www.tractorbynet.com/forums/attachment.php?attachmentid=318421&d=1369018069&thumb=1&stc=1

 

[Neat 1500]

sounds like a stuck governor rack in the injector pump.

 

[winston1]

I agree with Neat 1500. Try tapping on the injector pump. Might possibly free it up. If that doesn't work you may have to pull it. You can see the rack #17 in this drawing. Yanmar Tractor Parts: INJECTION_PUMP

 

[gweishaar]

Thanks Neat 1500 and Winston. I already tapped (somewhat lightly with a rubber hammer so as not to break anything) but will try again. The tractor is at my lake hose about 100 miles away. Is the thought that the pump is stuck or the governor? If I pull the injector pump will the governor be attached? Can I get access to the governor if I pull the injector pump? Pulling the injector pump looks straight forward - any tips? Will everything in the governor come out??? The parts cut on the governor looks complicated. Thanks.

 

[clemsonfor]

There is a spring or something i here these guys talk about when pulling it that you ahve to disconnet, dont just yank it out. Also not the shims behind it or whereever they are to keep it in time.

I am no expert just read stuff on here half paying attention. I think it too is a stick govener or something in that pump and nothing else.

Did this thing run prior to the dissasembly? Was it running right then?

 

[gweishaar]

There is a spring or something i here these guys talk about when pulling it that you ahve to disconnet, dont just yank it out. Also not the shims behind it or whereever they are to keep it in time.

I am no expert just read stuff on here half paying attention. I think it too is a stick govener or something in that pump and nothing else.

Did this thing run prior to the dissasembly? Was it running right then?

The engine ran well before I split the tractor (about 1 year ago) to replacewhat I found out was the wrong throw out bearing (or what was left of it) that a previous owner had installed without the steel bearing carrier. This created lots of squeeling, smoke and no way to take the tractor out of gear (that was an interesting ride).

I have installed a new clutch as well. I suspect that something is just stuck inside the tractor from sitting that long.

As I said I can operate the throttle mechanisn but it seems to just put tension on a spring that is concealed inside and supposed to pull on something else. No change of speed. The diagram I have on the govener shows lots of parts and is not clear on how to access or disassemble. If I try this I will pull the injector pump first, be very careful and take lots of photos and not wait a year to put it back together.

 

[kenmac]

If it ran fine b-4 you started working on it ,but it sat apart for a year and not run.IT would be my opinion that something in there just stuck form non use.

 

[winston1]

I have never done this, only stating what I believe to be correct. Note reference #16 in this parts drawing. I believe if you will remove that you will have access to the linkage. I know that Aaron with Hoye says to be gentle with that linkage so as not to damage the governor. I don't really think is is complicated although I have not personally done it. Yanmar Tractor Parts: BLOCK

 

[gweishaar]

I have never done this, only stating what I believe to be correct. Note reference #16 in this parts drawing. I believe if you will remove that you will have access to the linkage. I know that Aaron with Hoye says to be gentle with that linkage so as not to damage the governor. I don't really think is is complicated although I have not personally done it. Yanmar Tractor Parts: BLOCK

Thanks Winston. I thinkyou have been helpful to me before. Thanks again!

 

[jsal007]

On my tractor which also sat for a while...the linkage for govenor behind fuel pump did not move due to a roller spring stuck from old fuel...need to use penatrating oil to release parts but dont pull apart otherwise you will have to recaliberate pump.

 

[gweishaar]

Thanks JSAL. Where do I spray the oil to get to the roller spring? Do I need to pull the injector out just enough to spray it?

Where is Alice Tex.? We have some visitors coming to Va. this month from Paris Tex.

 

[winston1]

I'm not jsal007 but he may be talking about the injection pump plungers or guides. I believe he is just warning not to take the injection pump apart, rather just work at getting it freed up. Not saying not to take it out to gain access. Just what I think he is saying, may be all wet. :confused3:

 

[clemsonfor]

i read it as do not dissasemble the pump itself as well.

 

[gweishaar]

So if you look at my photo on the previous page, I will loosen injector tubing, take off the fuel supply tubing, loosen and remove the nuts that hold the pump on the tractor, note closely the shims & pull the pump out. I assume there is a connection somewhere in there to the pump so I will be careful not to break anything, disconnect the spring if possible, do not disassemble the pump, try to free what is in a bind and after freeing the bind, replace the pump in the reverse of how I took it out/off??? Can anyone confirm that has actually removed the pump on a 1500D?

 

[clemsonfor]

I may be wrong but can you even see the "plungers" by just removing them pump? i would thing taht there internal to the operation of the pump?

 

[winston1]

I may be wrong but can you even see the "plungers" by just removing them pump? i would thing taht there internal to the operation of the pump?

I don't know about the pumps on first hand experience but from my reading I know some people have had success freeing up their pump. Just looking at this picture of the pump I would think penetrating oil could be sprayed in the rack opening which should reach the little gears and some part of the plungers. Although we can't see the underside I know their are rollers under there that run on the cam. I would think penetrating oil in that area should also do some good. Finally and most importantly, don't take my word as "authority" on the matter. http://www.hoyetractor.com/mm5/merchant.mvc?Screen=PROD&Product_Code=IP-200

 

[S Putnik]

Assuming the IP is fuel lubricated as many are, LubroMoly Diesel Purge is a fuel additive that might help free your governor rack without removing the IP. You can run the stuff straight to circulate it trough the fuel system, let it sit overnight and start again in the morning with regular fuel.

It's a long shot, but might save several hours of wrenching.

If you do take the IP off, Berryman B-12 Chemtool works really well for dissolving fuel varnish.

 

[gweishaar]

So you think I can just unscrew the bolts and remove the fuel lines and pull the I pump out. Is anything else connected to the pump inside? I don't want ot break anything. Does the pump just run on a cam without anything else connected? That is what the Hoyt photo of the I pump suggests????????

 

[Barry 1]

Take off the cover plate(W/blow by tube) above the pump,and there should be a spring ?? hooked to the pump-don't stretch it or damage it. Never had to remove one yet-just repeating what I have read on other posts. The pump runs on a cam,but you have to disconect the linkage before you just unbolt it and pull it out.

 

[gweishaar]

Barry, and all thanks for the help. I will be at my lakehouse this weekend and will remove the cover plate as you suggested, remove the spring, remove the fuel lines, remove the I-pump while keeping a close eye on the shims, will not take the I-pump apart and try to free up what is stuck before replacing all the parts. This time I will take some photoes just to be sure when I re-assemble all looks the same.

Thanks again for the suggestions and help.