PTO

[atk_man]

What engine speed/PTO gear should I be trying to obtain to run a finishing mower on a B7100?

Has anybody heard of any aftermarket tachs?

 

[looch]

I think most will agree that you set the throttle high enough to get the job done, in your case cutting the grass. On my old B5100, I'd set it just shy of wide open.
Don't know of any aftermarket tachs specifically designed for tractors. I've heard of one type that uses the engine damper (harmonic balancer). You install a small "sender" on the damper and mount a reader to the block. Every time the sender passes the reader you have one revolution. I don't see why you couldn't install one of these on your machine (unless the price is prohibitive).

 

[atk_man]

Which gear? (I haven't tried yet, I'm just looking for a few pointers before I begin.)

Thanks.

 

[looch]

I seem to remember from another post that your machine is a '79. If this is the case, it probably has the same (or comparible) tranny as the '81 B5100. I would run mine in third gear, low for the thick stuff and first gear, high for weekly cutting. 2nd gear, high with the throttle wide open was just too fast for lawn travel even when I wasn't mowing.

 

[atk_man]

Thanks.

Can I safely run the throttle wide open? What should the rpm be when the throttle is rammed right to the stop?

One more thing, 1, 2 or 3 on the PTO?

 

[mbjacobs]

Read a message on Yahoo KOG from a guy that installed a tach on a B7100, doesn't sound easy.

http://messages.clubs.yahoo.com/clu...d=kubotaownersgroupkog&sid=1600062557&mid=226

Maury Jacobs

 

[Thomas]

When useing B7100HST w/the rear mower I go by feel.
Depending on the surface and what I'm cutting thats when I section the comfortable tractor speed and rpm's
About 2/3 throttle -+/

Thomas..NH /w3tcompact/icons/wink.gif

 

[looch]

<font color=blue>Can I safely run the throttle wide open</font color=blue>

Safe for the tractor, but I'd wear hearing protection/w3tcompact/icons/wink.gif.

I'd be guessing the RPM at full throttle - probably somewhere around 2600?

<font color=blue>1, 2 or 3 on the PTO</font color=blue>

Sorry, can't help you there. Mine was a MMM running off the front, electric clutch PTO - one speed fits all. Most (all?) 3ph mowers like 540 RPM at the input.

 

[Bird]

Atk man, the "standard" recommendation from dealers seems to be to open the throttle wide open, then ease off just enough to notice the change in sound; that'll be "PTO" speed which is only a couple hundred rpm below wide open. However, the tractor has a governor and it won't hurt it to run it wide open. As for which gear; whichever one gets the job done the way you want it without lugging the engine.

 

[RobertN]

On these tractors, isn't there a governer that will limit the rpm? I have never looked on my B8200, just always assumed there was. I have never had need to really crank her up.

RobertN in Shingle Springs Calif

 

[hayden]

Boy am I getting confused. You want to know what engine speed and what PTO gear to use.

From the responses I gather that a 7100 does not have an engine tach - Is this correct?

I'm also gathering that there are 3 PTO gears to choose from. Correct? Are they labeled in any way other than "1 2 3"?

For a mower, you'll get the best cutting performance with the PTO itself rotating at 540 RPM. Assuming you have 3 PTO gears and infinite engine speed selection between about 1000 and 2600 RPM, there should be 3 engine speed/PTO gear combinations that result in a PTO speed of 540 RPM.

I've seen other tractors that label the PTO speeds along the lines of "540", "760", "1100". What this means is that at full engine speed, you will get 540, 760, or 1100 PTO RPM respectively from each of the gears. One of your PTO gears is the "540" gear, but unless it's labeled or you have the manual, it will be a trick to figure out which one.

Anyone out there have a manual for the 7100?

Once you know the Full throttle PTO speeds for each PTO gear, then you can calculate the PTO speed at lower throttle setting, but without an engine tach, it will just be guesswork.

 

[Bird]

Peter, atk man's profile doesn't say which B7100 he has, so I don't know about all the PTO speeds available, but the '95 B7100 had two PTO speeds (540 and 1000). I don't think any of the B7100s came with a tach (one dealer told me he could install one for about $200). Speaking of the gears (1, 2, & 3), I'm assuming is talking of the transmission gears on a geared tractor. At least the '95 B7100 was a two range HST.

 

[Egon]

atk_man: Re finish mower rpm.
I have a b7100 hst[93]
At 2800 engine rpm which is full throttle and governed,I beleive, these are pto rpm's
Rear: 540 or 850
Mid: 2450
When your mid pto is engaged the rear is also engaged.
When the rear is engaged the mid is not.
With a midmount 60 in. finishing mower I remove the loader and any three point implements, use high range in 2 wheel drive and have the throttle slightly backed off from maximum. I use the HST to regulate forward speed for quality of finish cut.
Egon

 

[hayden]

I think we need to know these details to help him rather than confuse matters worse. I could certainly believe the "1 2 3" gears are transmission, not PTO. I've also only seen 2 speed PTOs, but my sample size is admittedly small.

 

[Anonymous Poster]

I have a L-245 it has 3 Pto Speeds
#1 540
#2 750
#3 1000

Not 100% sure on #2 & #3
but think am in ball park
I mow in #1 Wide Open
Turns about 2900 RPM
Which is probably a little over 540 RPM @ PTO
PTO speed is 540 RPM @ 2600 Engine RPM
Makes Land Pride Mower Sing

JWB

 

[hayden]

There we go - learn something new every day.

 

[Anonymous Poster]

The manual says to use No 1 speed for all PTO implements except special implements available in Japan which may use higher speeds ie 2 or 3.