YM3000 injector pump linkage/engine run away

[WileyG]

My throttle on my YM300 has become inoperable and the tractor only runs wide open in a run away state. I have taken the throttle linkage loose from the lever on the injector pump and there is spring tension on the lever from inside the crank case but it does nothing to control engine speed. This evening I'm going to remove the inspection plate and see if I can determine what has come loose. What should I be looking for in there and can I resolve this problem thru that opening with the plate off?

 

[Coyote machine]

First, Welcome to TBN. Sorry for your situation too. It sounds like your IP rack, (internal to the pump) is stuck wide open. I'm not familiar with your specific tractor, nor it's IP. I suggest you call Conestoga Diesel in PA, to ask them what to do and how. They have provided services for Kioti owners here at TBN, and are familiar with all kinds of IPs and tractors.
I wouldn't start the tractor until you can get the pump to run it at normal speed. This may entail pump removal and repair, which will be less expensive than rebuilding a blown engine.

 

[WileyG]

Thanks for the welcome. I used to be on here but forgot my un and pw so I just re-registered.

I was hoping that somebody would respond with a pic or firsthand knowledge of the internal linkage.I'm quite mechanically inclined, have rebuilt engines, have tools, etc but gasoline engines have been my forte.

 

[woolyAcres]

Hi WileyG-

You might get a few answers by posting in the Yanmar specific (Yanmar OLD) forum. I know there are some folks there that know these machines inside and out.

Sorry I don't have anything better to offer.

 

[Coyote machine]

Here's what I'd do. Remove the inspection plate with the tractor off. See if you can access the rack visually or physically, or both. Take pics, post them, and wait for replies. If it seems possible to move the rack, without doing further damage, you might try doing so, but I doubt you will be able to without further dismantling.
The old Yanmar forum could be a good place to repost this thread too.

 

[Barry 1]

This is the "Rack" on the pump. It has a flat lever attached to the pin,with a little bushing and a hair pin. The rack is probably stuck? It should move freely in and out of the pump. Take off the breather cover above the pump and you can see it and maybe free it up.Or you might have linkage problems?Won't know till you look.

 

[GerryE]

Had one doing the same thing, The little hair pin Barry 1 mentioned had fallen off and the engine ran away as soon as the engine started.

 

[WileyG]

Thanks for the replies. I ended up having to pull the pump. The gear on the first injector had somehow become disengaged from the rack and stuck the rack. She's now running like she always had before the issue.