hey guys need help when its idling or about half throttle it seems like it runs good and smooth pull the throttle open and it has a pop to it not running smooth thanks for any help

worn out cam lobe? check to make sure all valves opening and closing is a good place to start along with valve adjustment.
injection pump problem?
need longer story.

Sounds like one of the rubber seals on the pump driveshaft is getting weak. I do not remember if you took the pump off or not, but if you did perhaps one of the seals rolled back during installation. Good luck.

yes I did take the pump off I was very careful putting back on making sure the rubbers got put in good yes the pump does need rebuilt I didn't no if there was an adjustment screw to get it more fuel at wide open it pops like its starving for fuel wide open

the pump will not make it pop, it has to be in the valve train. have you checked that? when did this popping start?
but then your popping description may be totally different than what I call popping. when you have a worn cam lobe it will pop through the intake.
yes there is fuel adjustments, but tractor should be on dyno for that. why was pump taken off? what was done to it? give complete story.

the pump was took off it got stuck on the inside had bad fuel in the tractor I haven't had it mabe 3 weeks it was poping when I bought it there is some blue smoke coming from exhaust pipe the tractor had ben setting awhile not sure how long when I got it it started right up loaded on trailer shut it off it wouldn't start took the pump to the pump shop they unstuck it put it back on with new rubber seals im sure there in right there is a little slobbers coming out of or around no1 and no2 injector runs smooth low idle and half throttle full throttle missing or popping to me it sounds like fuel miss that's about all I no at this point thank u for your help

You might want to pull the injectors to have them checked.I don't know what the popping sounds like, but advancing the pump timing a couple degrees can also fix high rpm no load missing.

I can't hear your tractor run from here but the first thing I would suggest is make sure the load advance is advancing the timing like it is supposed to. You need a timing window on it to check. It should advance two marks on the window at all no load speeds and retard one at half load, and two at full load. I know you can't watch it unless you have it on a dyno but there are other ways of getting a good idea if it is working correct or not. With window on, engine running low idle I adjust for the full two mark movement. Then I open throttle wide open very quickly and watch the cam for movement. It should retard about one mark. This is a simple and very very often overlooked adjustment on those load advance pumps. Many a pump has been taken off for repairs and more often injection nozzles when all that is wrong is the advance need adjustment. Some people even advance the static timing and that makes the engine sound right but that is totally the wrong way to do it as you want it to retard under load on that engine. The adjustment is on the governor spring guide screw. Directly above the head of pump, on rear side of the top part of housing. Has a lock nut on it . You can just turn it in a half turn or so even without a window to see if that makes it hit properly at full throttle. The guide screws is tapered an the metering valve is constantly rotating against it so it wears a flat spot on guide. A slight turn and you are on a new spot.

Thanks guys

X 2 what pete said. If you can get it on a PTO dyno it can be set accurately. I use the batwing gauge, but the window works too, just harder to see. Should be full retard at full load, full 4 degrees at no load and 2 degrees at 1/2 load. If it does stay retarded at all times it will pop badly at no load, and sound fine at full load. Be careful when locking the stud nut, housing threads can be stripped easily.