Hi All, My 480c was running good, always started right up. Yesterday while digging a stump out it stared to stall. Seemed like it was starved for fuel. I could restart but it would stall shortly afterwards. From what I’ve been reading I think it might be the injector pump. Mine has a Roosa Master DBG pump. My guess is the check valve is stuck due to parts of the flex ring breaking off. I’ve seen others suggest removing the line to the check valve to see if that improves the running to see if it the pump/check valve will a the really the problem. I guess that’s my next step. If the pump needs a rebuild what do folks recommend? Do it yourself? Send it out? If send out, where? Cost to bet it rebuilt? Thanks!!
Your diagnosis is correct. Remove the line, start it up and if it doesn’t stall, the line is clogged.. Same with the return connector, if it stays running, the connector is clogged.. Sometimes u get lucky and it’s just some debris in the pump, but more often it’s a broken flex ring. U can also remove the side windows on the pump and hold a wad of paper towels under it and let it drain over the towels, if u see a bunch of black specks, it’s usually the flex ring.. U can contact me directly at: My screen name at aoldotcom in your home mail service..
Thanks TPG. I had a little time tonight to look at it. I removed the return line fitting and it started and stayed started. I did not see any debris in the check valve but hard to see. I blew it out with air and I could see the glass ball move. I put the return line back on and started it up again. It ran but seemed to run a little rough, surging at idle. I ran it around the yard for about five minutes then it started stalling again. Can we conclude for sure the pump needs a rebuild now or should I take the side cover off to see if debris there?
Nothing is For Sure until u find bits of flex ring.. If u feel comfortable taking off the side cover, do it.. u have to drain the pump before u pull it off anyway..
I had a 580C long ago and it had a stalling issue. Found it was the little glass ball stuck. I guess it was a check valve dead on top of pump. Loosen line, it leaked fuel, to get tractor out of field we popped out the glass ball and ran for years that way. Hope this helps. Jim Conley Florida
Thanks for the reply. Have some plastic in the pump so I think the flex ring is breaking apart. I’m going to have it rebuilt if I can ever find the timing marks.