Mowing hi-gear vs. low-gear mowing

[RoyJackson]

wow.. full throttle for 540 pto? I would have expected 2/3 or 3/4 at most.

soundguy

I dunno, Soundguy...my ol' 670, 790 and current 4400 tachs all go to 3000 and the PTO marks were between 2600 and 2700.
Reckon you're so used to that olden golden iron that tached out to about 2000 RPM.

 

[Soundguy]

I have new iron as well.. 2/3-3/4 tach is pto on my largest tractor.. and it's only about 8ys old now. Onlt problem with putting pto at MAX throttle is that if you need to add throttle in a tough spot.. you can't

on your tach that goes to 3000 is there a redline anywhere? or does the redline start at 3000?

soundguy

 

[RoyJackson]

I have new iron as well.. 2/3-3/4 tach is pto on my largest tractor.. and it's only about 8ys old now. Onlt problem with putting pto at MAX throttle is that if you need to add throttle in a tough spot.. you can't

on your tach that goes to 3000 is there a redline anywhere? or does the redline start at 3000?

soundguy

No redline...I just figured (but don't know) that's the RPM the engines are governed at.
Mowing (or brushcutting) and chipping are the only tasks that I run in excess of 2000 RPM. The hand throttle is normally set at 1500 and I'll use the foot throttle if I need more RPM for short periods.

Thse are all smaller engines then in your tractors. IIRC, the 670 was about 60 cid, the 790 was 91 cid and I believe the 4400 is between 90-100 cid (give or take a few cubic inchs). All 3 cylinders. I expect your tractors all have over 100 cid and are probably 4 cylinder.

 

[Soundguy]

No redline...I just figured (but don't know) that's the RPM the engines are governed at.
Mowing (or brushcutting) and chipping are the only tasks that I run in excess of 2000 RPM. The hand throttle is normally set at 1500 and I'll use the foot throttle if I need more RPM for short periods.

Thse are all smaller engines then in your tractors. IIRC, the 670 was about 60 cid, the 790 was 91 cid and I believe the 4400 is between 90-100 cid (give or take a few cubic inchs). All 3 cylinders. I expect your tractors all have over 100 cid and are probably 4 cylinder.

yep.. 304 ci / 4 cyl for the biggest one.. 256/4 for the next biggest one.

If your tach shows no redline.. I'd almost bet that is a 'dumbed down' setup. IE.. the redline starts at the 'end' of the tach meaning your pto near max rpm is really more like 2/3 to 3/4 rpm of full engine range if you had a tach that showed a redline.. etc.

just a guess anyway.

soundguy

 

[dmay]

As a very general statement, high gear = transporting, low gear = working. You will find what works best for you and your ground/grass conditions but I would start with your dealers advice. Low-gear full throttle will always get the job done. I'd even try pulling back from full throttle and stick at rated PTO rpms. If you ground speed is good, why run full throttle?

 

[GardenFence]

OK, that about sums it up. Thanks[to everyone for your helpful advice.




QUOTE=TripleR;2005611]As said earlier, I owned a BX2200 for six years and was also told to run it at full throttle which I did. My son in law now owns it and runs it that way. My BX2660 has a PTO speed of about 2950 for MMM and 3000 for rear PTO; may be off 50 one way or the other. With wide open being 3300, I wouldn't be far off by running it wide open.

Yep, the correct ground speed can determine the quality of cut which will vary with different types grass, height, humidity etc. In the end, whatever combination, within reason, of tip speed and ground speed that give you the desired results will be OK. Some of us get too tied up in minutiae.[/QUOTE]

 

[bp fick]

I mow at 2950 RPM or 90% ?? of the maximum of 3200 with my BX. I want the cooling system cranking. Puttering around at lower RPM can cause some heating issues with the BX according to many reports here. That is pretty much PTO speed. Less RPM may sound like it would save your engine, but I can't agree. Kubota seems to want these BX engine to run, so run it is.

As for the Hi or Lo, alot depends on your ride comfort too. Our land is not city or suburban type smooth. It just isn't. My lumbar doesn't appreciate being bounced around and I see no need to save 10 minutes of mowing time while beating both my body and my equipment to do so. That's just me.

Finally, working in Hi makes the HST whine more and I've had all the whining I need. No need to whack trees, buildings, and other obstacles by ripping around at speeds either. In Lo, my R4 tires have never marked the grass either.

YMMV, we're just sharing here.

 

[tractorman14]

It should depend on how thick the grass is. The thicker and taller the grass the more throttle you should have and the slower you should go. The shorter and thinner the grass is the faster you can go with less throttle.

 

[BrianR]

I have mowed for 7 years with my BX in Hi range with no issues. I only drop it to low range when any of the following conditions exist:

1. Tall, thick grass
2. Hills/ditches
3. Rough ground
4. High ambient air temps (80's or higher)

My lawn is smooth and mostly flat so I can mow at a pretty fast pace and still keep the hydro cool enough. If it is really hot out, I run low gear to keep the hydro cool.

 

[amigauser]

I have mowed for 7 years with my BX in Hi range with no issues.

I also mow in high range with my BX1860. I find that I keep the petal to the floor in low range (just to slow) so I use high range but not a lot of the pedal travel. It seems to allow me to adjust my speed much better.

Since my BX is basically new, 18 hours, I am only running it at 2600 for mowing. I also try to very the RPM some what to break it in. Once I complete the 50 hr service I plan on running it at full PTO speed.