3-Point Hitch Engine stalls when engaging Bush Hog mower

[Pilot]

Haven't used my 770 PTO mower much, and it has sat for a year or two. Used the tractor a couple years ago to till with no problem. Stored inside.
Hooked up the mower today, fired up the tractor & all it wants to do is stall the engine when I slowly engage the PTO. Run it up to over 2,000 rpm and it still stalls.
It has had a hydraulic problem for a long time, the 3 pt. hitch will slowly drop down and it has done that for 10 or 15 years. Had the Massey dealer look at it (he was closest) and he couldn't find a problem and they talked to a retired JD mechanic & he was no help.

Any suggestions?
Thanks.

 

[bullbreaker]

Could it be something binding up underneath your bush hog like wire ? Do you have a shear bolt on hog or a clutch ? Could your gearbox be frozen on your hog? Have you treid engageing pto without any pto shaft to it to see if it stalls ?

 

[BoylermanCT]

I always start my PTO at lower engine RPMs like 1200-1500. Then throttle up to full PTO speed.

 

[CobyRupert]

Step 1.
You need to test the tractor and the bush hog separately to see which is problem.
If you unhook pto to bush hog, can tractor turn pto on?
With mower raised, can you turn the mower blade?

 

[jaxs]

Step 1.
You need to test the tractor and the bush hog separately to see which is problem.
If you unhook pto to bush hog, can tractor turn pto on?
With mower raised, can you turn the mower blade?

What ^he^ said and with pto disengaged, does tractor take off from standstill without bogging?

 

[CobyRupert]

.... but if i had to guess, might be growth in fuel tank from sitting around for 2 years clogging filter and it’s fuel starved.