D 17 Diesel

Hey guys got the 17 back together and got it running finally. The problem is it runs great at idle but about half throttle it  breaks up and runs really ruff white/grey smoke skips pretty good too, slow it back down to an idle and it runs fine. I have done nothing to the injection pump its self, while it was apart i put a new head gasket in it pulled the injectors an had them pop tested all turned out good. new injector seats new filters and new line from filters to pump. It ran fine before all of this just wondering if anyone had any input on what might be wrong. While it was running i cracked all the injectors and got fuel out of all of them but it looked like it had air in it. I Have no fuel leaks anywhere.
Thanks again dennis

thanks for the reply, the pump was never off the tractor or played with so the timing should still be the same no? Ill give it a try and see what happens it starts really good right now just fogs white smoke and skips also seems to be reving up a few 100 Rpms for a second and them returning to normal a "gallop" i guess i cracked all the injectors and got some black stuff out of them, the whole system was drained and capped for about 4 months so i dont know where it came from.
Thanks again dennis

If you raised injector popping pressures, you have in essence retarded the timing just a tad.

My Uncle told me since my great grandfather bought my D17 diesel brand new from dealer back in 1963 it always smoked gray/white smoke when you opened it up to half throttle or wide open, but at idle or a tad above it would run normal and it always seemed to have its full horse power. I don't believe it has ever had the fuel pump removed at anytime or played with other than new O rings put on the injector lines. It always starts after a little shot of either and runs great, and this tractor ran all summer long in a hay field of New York six days a week probley five to six hours a day. I believe it has had a few motor jobs in the past, one that I remember helping my Uncle with atleast.

Dennis, I am no diesel mechanic by far, but ran into a similar issue with the D262 motor in a D-19.

The whole front end and timing cover must come off to jump a tooth. BUT, I can't/refuse to believe that it needs a whole tooth advance to make it run smooth. Better get the pump off and rebuilt before you go into the engine. I believe you have an internal pump issue.

I could work on it for you. DB pumps usually run around $500 for a freshen up.

Timing could be a pressure problem from inside the pump, dirt, debris inside pump. Old age and sitting for awhile related to pump problems. I understand nothing else was messed with while you had the head off but there are other issues that can make a pump do lots of funny things. I'd pull the injectors and send them off with the pump to make double sure they are tuned and set up correctly.

If you disconnect some return lines and find black particles, govenor ring is going bad. Very common on these Roosamaster pumps......