RPM & performance issue 2022 2515R(H)

   / RPM & performance issue 2022 2515R(H) #1  

esz

Member
Joined
Nov 25, 2015
Messages
26
Location
Colorado
Tractor
Kubota L2550DT Kubota BX2200D Branson 2515H
I recently purchased a Branson 2022 2515H. I have 15 hours on it and have a question on engine RPM & performance. My engine will only throttle up cleanly to 2000 rpm. Above 2000 it runs rough and maxes out at 2200. According to the tach (could not find any instructions in the owners man related to RPM's) I need 2400-2600 to get the PTO to turn 540.

I discussed with the dealer service department and will take it in when I can.

Any idea what the issue is? Also, what is the reference to 540E on the tach?

Thanks
2023-02-02 08.46.29.jpg
 
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   / RPM & performance issue 2022 2515R(H) #2  
540e refers to an "overdrive" speed for your pto. Somewhere on your tractor you have a lever or switch that will engage it. What it does is gives you 540 RPM on the PTO shaft at an engine speed of around 17 or1800 rpm instead of 2500 rpm, I never take mine out of 540e.
Your dealer should have schooled you on that.
 
   / RPM & performance issue 2022 2515R(H) #3  
540e refers to an "overdrive" speed for your pto. Somewhere on your tractor you have a lever or switch that will engage it. What it does is gives you 540 RPM on the PTO shaft at an engine speed of around 17 or1800 rpm instead of 2500 rpm, I never take mine out of 540e.
Your dealer should have schooled you on that.
Just to expound on that - as cougs said it's an overdrive, so while it's driving the PTO at 540 at the lower engine speed of ~1800, it's got much lower torque.
The "E" is for "efficiency" or something like that; this setting is useful for when you need that 540 PTO RPM but what you're running doesn't need a ton of power, so you can operate the tractor at lower revs to conserve fuel and your own hearing.

I'm occasionally tempted to run my rotary cutter on 540E when I'm not in taller grasses, but haven't bothered yet; the job doesn't require a lot of power & torque so letting the tractor be more chill while spinning the cutter at a proper rate would be fine (though it would suck if I started cutting tall thick stuff).
 
   / RPM & performance issue 2022 2515R(H) #4  
I run the cutter in 540e when I'm cutting the part of my land that's closer to neighbors. It's quieter. When running the chipper it's in 540 as that uses all the 3725's power and then some.

The revving out problem could be a fuel or air flow issue. Does it make any smoke when its running rough at higher rpms?
 
   / RPM & performance issue 2022 2515R(H) #5  
The 2515 only has the regular 540. No 540 Economy. For some reason, Branson didn't really update the dash for the 2515 nor I could find any info on the manuals as to what Engine RPM gets the 540 at the PTO. Technically those marks on the dashboard are irrelevant for your tractor.

I think that the PTO gear ratio is different from the higher HP models since this model is derated to 2100 RPMs because of emissions. Also and for the same reason, they're running the engine with so little fuel that it acts up at high RPM. Your dealer should be able to make the necessary adjustments on the injection pump to fix that. I've seen similar experiences from other people regarding this issue, along with the fix.

EDIT: Checking the part numbers at the parts manuals, looks like they use the same PTO gears as the higher HP models, which means that tractor never really gets to 540, only to about 452RPM at 2100 engine RPM. This explains why on a video I saw recently of a 2515 with a snowblower, it looks like the PTO is rotation slower than it should.
 
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   / RPM & performance issue 2022 2515R(H) #6  
Branson used the same tach on different models. You don’t actually have 540E as others have said.
 
   / RPM & performance issue 2022 2515R(H) #7  
My first thought would be fuel related. Either bad fuel, dirty fuel filter, plugged, etc.

I doubt you could get the air filter dirty enough to cause these issues in 15 hours, but it's possible I guess. Take the air filter out and blow it out from the inside out with compressed air.

Does it only rev roughly while under load, or even when revving it while unloaded?

Is the fuel tank full ( 😁 )?
 
   / RPM & performance issue 2022 2515R(H) #8  
The 2515 only has the regular 540. No 540 Economy. For some reason, Branson didn't really update the dash for the 2515 nor I could find any info on the manuals as to what Engine RPM gets the 540 at the PTO. Technically those marks on the dashboard are irrelevant for your tractor.

I think that the PTO gear ratio is different from the higher HP models since this model is derated to 2100 RPMs because of emissions. Also and for the same reason, they're running the engine with so little fuel that it acts up at high RPM. Your dealer should be able to make the necessary adjustments on the injection pump to fix that. I've seen similar experiences from other people regarding this issue, along with the fix.

EDIT: Checking the part numbers at the parts manuals, looks like they use the same PTO gears as the higher HP models, which means that tractor never really gets to 540, only to about 452RPM at 2100 engine RPM. This explains why on a video I saw recently of a 2515 with a snowblower, it looks like the PTO is rotation slower than it should.
The manual shows 533 rpm vs 560 for the other models?
1675386866247.png
 
   / RPM & performance issue 2022 2515R(H) #9  
The manual shows 533 rpm vs 560 for the other models?
View attachment 782071
I did the math using the same ratio as the other models and it came down to 450 PTO RPM and 2100 engine RPM, which seems to be what they rate this engine at. The smaller gear is 14 teeth and the bigger is 65.
 
   / RPM & performance issue 2022 2515R(H)
  • Thread Starter
#10  
So what I'm hearing, is this engine is not supposed to turn above 2100 rpm? And, my PTO will only turn 450? What engine rpm would it take to get 533?

It almost feels like a governor kicking in at 2100. I wonder if the dealer can fix that.
 
 
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