r JD/ Yanmar injection pump question

[JoeJChin]

Anybody out there familiar with the following type injection pump ?

link to picture

http://www.jhdiesel.com/Mvc-017s.jpg


It's a Yanmar pump off a JD 750 compact tractor .

I was having trouble getting the tractor started , and ended up pulling the pump off of it .

I don't think the pump is working properly .

After all the normal bleeding purging etc trying to get the tractor started again ( 20 minutes after shutting it off )

I pulled the access cover off the side of the gear case , and it doesn't look like the rack is moving in the pump when i move the throttle lever back and forth .

If you look at the right hand picture , what i have seen called the rack , is the rod , with the pin sticking out of it .

The pin is what sets into the yoke of the throttle arm .

I pulled the pump out , and i can move the rod , but it moves very hard.
Kind of takes two thumbs on it to make it move .

The only reference i have seen , is that it "should move freely" .

I was wondering if anyone here has had one out and can tell me how "freely " it is supposed to move , and if there is any reason

it would get so hard to move while i was running it .

thanks

Joe

 

[Ken]

Unable to give any reason for failure of pump But I would take it to a diesel injector shop to be checked.
since already have it removed. mark any points to be remembered and let some one experanced give a suggestioin.