b6100 rpm's?

shane772

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Feb 22, 2016
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Tulsa, Ok
How do I know what rpm I'm running? More specifically, I want to run the rotary mower and don't know where to put the throttle or what gear to use.

I thought about buying an aftermarket hour/rpm meter like I've installed on my mowers but, I assume I don't need that if I know the proper way to operate the tractor.
 

85Hokie

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Jul 13, 2013
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How do I know what rpm I'm running? More specifically, I want to run the rotary mower and don't know where to put the throttle or what gear to use.

I thought about buying an aftermarket hour/rpm meter like I've installed on my mowers but, I assume I don't need that if I know the proper way to operate the tractor.
Too get the mower to "tip speed" you will need to run it almost WOT - notice I said almost......if you do some research and look at tachometers - you'll see some have the 540 rpm mark stuck somewhere about 90% or so of WOT.

My advice would be to engage the blades, run it up all the way and then pull back a bit.

Many people truly believe that cutting at a slower RPM is better for everything.......ignorance is bliss! - when engineers (those who think stuff up) design a piece of equipment, they must take in consideration a lot of intangibles. So they design the mower to have a gear box to be turned at "x" speed so that the blade tip speed is at "X" speed.......all that boils down to what the engine dishes out, and thus the engine must match the "x" speed.

Diesels are torque driven machines, they have a hellva lot more torque than gassers .....but if you if cut grass at idle, you are loosing all the advantages of the diesel.

Diesel generators do not have a variable "speed" - now true a governor is in there to tweak it , but once started it runs at that RPM that makes the most "power" to do the job...........cutting grass should use the same principle!:)
 

D2Cat

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85Hokie said it real simply, "My advice would be to engage the blades, run it up all the way and then pull back a bit."
 

85Hokie

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What about gears? High or low? Which gear? It's pretty tall right now.

Your engine sound and vision of the grass will tell the story......

too much and the engine will moan and decrease throttle, and your grass will look laid over rather than cut, if 6 speed - I'd start in 2nd and go up or down according to the cut - now more importantly - the height of cut will have a lot to do with it too.

If tall now - you might need to raise deck - cut in lower gear, then come back and lower deck and cut again!:D;):)
 

shane772

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Feb 22, 2016
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Tulsa, Ok
Think I got it. I'm planning to cut it as high as it will go first and see how it goes. Headed out to sharpen blades, check grease, etc. I sure appreciate the quick responses, thank you!
 

North Idaho Wolfman

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Engine at 2800 RPM's is perfect, so yea WOT and then back a smidge or so. :D
You didn't say if it was a mid or rear mounted mower, or if mid if it was run from a belt off the front of the motor or off of a Mid PTO.
The front motor driven unit has no speed adjustment other than the RPM's of the motor.
While the rear and mid are adjustable via what speed you set the output to.
The b6100 has a variable rear of 540/750/1000
The B6100HST has a variable rear of 540/850 and a set mid at 2450.

So make sure you set it accordingly or it will be spinning real fast, like self destructive fast!!
 

shane772

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Feb 22, 2016
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Tulsa, Ok
Yeah, guess I overlooked the options I didn't know existed, lol. This is a rear pto driven mower. I've read through the owners manual and looked a lot on here for info. I think I pull the pto lever toward the rear and this will be 1st gear (540 rpm), adjust throttle and mow.
 

farmall1942

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B6100, B9200, Grand L 4240, 2-ZD326's, AT70S Tiller 1942 Farmall H, 1954 Super C
Feb 25, 2016
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RISING SUN
I have been known to have a 4 foot pull type John Deere gyramor cutting pastures at about a foot tall in 5th gear almost wide open on my 6100 but i have my top rpms opened up some. So its probably about wide open.