JD X720

[JD755]

That's how my old JD 430 clutch worked, and I always lowered the RPM as the manual said to. Your explanation of changes to accommodate the PIO switch makes sense to me.

 

[John_in_TN]

The mid PTO on the X700 family in driven off the hydrostatic transmision. It uses an electrically actuated hydraulic clutch. This system provides some cushinioning effect to engagement. My X740 has no problem starting the 62" deck from a full idle (unless the engine is cold). The deck also seems to engage very smoothly at full engine speed (more cushioning effect). I usually lower the RPM before engaging but full RPM doesn't appear to cause any problem.

 

[jcmseven]

I bought an X720 for my dad, which I traded on a 950 and 2320 with 54d combo for mowing at his place and others down his way that I help. I believe this is a statement to appeal to the inexperienced user out there and nothing more. I can tell you without doubt that the 720 will start the mower deck from a dead idle, but probably no one is more the subject of that statement than my dad. These machines have a "cushioned" PTO engagement and one can easily start them at WOT, though I never do. As most of us know, these machines are meant to mow at WOT, or close to it, to achieve the best performance and advertised blade tip speed. When my dad, who is 80 and has some very mild dementia, first used his machine after instruction, he called me to complain it did not cut well. I went to check things out and asked him to repeat exactly the steps he did before. He did, including mowing a couple rounds at idle. I truly suspect that JD recommends this in part knowing it likely would not hurt the machine and to say they instructed owners to actuate and mow at WOT. I still am a strong believer in being no more than 1/2 when starting the PTO and going from there. It is not a matter of power, though, as the 720 has plenty to do this even if one were sitting in thick grass at the time.

John M

 

[will v]

A friend of mine had, I believe, a 445 gas that he said he always had to engage his MMM at full RPM or the engine would die. When he got a 2520 I noticed he was still doing that. I checked his manual and it said to reduce RPM for engagement. He did and it worked fine. I would expect the engine in the X749 to handle reduced RPM engagement just fine, but I see the exact same words in its manual as the X720 about using full RPM. Maybe there is something else we don't know about, although I'm sure you will try the reduced setting first. If that works I would stick with it.

Interesting - I have a 445 and have the rpm's reduced all the way down to almost idle when I engage the pto and then ramp up the throttle. Engine doesn't bog the slightest.

If I engage the pto with the engine at full song it gives the whole tractor a **** of a jolt.

 

[revitupfaster]

I have an X495, and it doesn't seem to matter what the throttle is set at when engaging the PTO. The mower blades will start fine at lower throttle settings, but even at a higher throttle setting, the engagement is smooth, with absolutely no "Jolt" at all.

It feels to me like the engine RPM's automatically reduce when I pull the PTO button, then ramps up again to whatever the speed was set at.

I also just got a 2520 with the 62D deck (virtually the same as the 62 on the X495) and it seems to engage the same way.

REV

 

[raymondwagner1]

i just bought a x720 they told me at low rpm u could damage or break the crankshaft they said at least 2 3rds throttle. the torq is low at idle so it seems to me 2 3rds to full is best.

 

[jenkinsph]

I have only mowed two times with the x749 but I am able to engage the deck at idle or full speed without any shake. Much smoother than the old 100 series which would really grab fast.