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Comprehensive Power/Speed Adjustments
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First things first, make sure your idle lever has at least spec low idle and high idle, 1200-1300rpm and 3700-3800rpm. My engine throttle without cable was set at the factory 1250 and 3750rpm. The idle lever cable failed to deliver the high idle of the engine. This problem requires trying different throttle holes and tweaking the cable mount so the idle lever has the full range from high to low.
Next step is to make the pump squash plate adjustment. This should be made at high idle on jack stands with the squash plate just moving the wheels forward then back slowly until they stop. This adjustment is described in detail elsewhere on the site.
Now make sure the treadle pedal cables are adjusted for the correct free play and the wheels do not move in high idle. While still on the jack stands in high gear the treadle pedal should achieve about 30mph fully depressed forward and about 8mph fully depressed reverse, if not make those adjustments.
Now off the jack stands the HP Commander are made as per the Bobcat Dealer.
FORWARD TRAVEL RPM CHECK (PERFORM LOADED FOR CAB VEHICLES, UNLOADED FOR NON-CAB):
This check verifies the horsepower management system is functional and adjusted correctly for optimal performance. The command torsion spring bolt can be adjusted in quarter increments beyond the baseline setting below to match personal preference or based on accessory loads and vehicle usage.
1. With transmission in HIGH range on level asphalt depress the travel control pedal to the full forward position with a quick fluid motion.
2. The engine RPM at 20 mph (32.2 km/h) should be in the range of 3400-3600 RPM for loaded testing and 3550-3650 RPM for unloaded testing. If engine RPM is not within specifications proceed to steps 3-6. If the horsepower management functionality is within specification, proceed to the FORWARD TRAVEL SPEED CHECK
3. To decrease the engine RPM (increased engine pull down), loosen the command torsion spring bolt nut (Fig.1 Item 6) and tighten command torsion spring bolt (Fig.1 Item 5) ｼ turn.
4. To increase the engine RPM (decreased engine pull down), loosen the command torsion spring bolt nut (Fig.1 Item 6) loosen command torsion spring bolt (Fig.1 Item 5) ｼ turn. Note: This setting can be adjusted to match user preference, if desired. Tightening the spring will result in increased engine pull down/lug and may require more modulation of the travel control pedal when under load. Loosening the spring decrease engine pull down/lug under load.
5. Repeat steps 3 - 5 until the RPM is within specification. If Forward Travel RPM is within specifications proceed to FORWARD TRAVEL SPEED CHECK.
FORWARD TRAVEL SPEED CHECK (PERFORM LOADED FOR CAB VEHICLES, UNLOADED FOR NON-CAB):
This check verifies the horsepower management system is functional and adjusted correctly for optimal performance with a full accessory load. The command torsion spring bolt can be adjusted in half turn increments beyond the baseline setting below to match personal preference or based on accessory loads and vehicle usage. On straight, level asphalt or concrete, mark off a distance of 250 feet (76.2 meters) for non-CAB/HVAC models and 300 feet (91.44 meters) for CAB/HVAC models.
1. With transmission in HIGH range depress the travel control pedal to the full forward position with a quick fluid motion. Vehicles equipped with CAB/HVAC should accelerate from 0-20 mph (0-32 kph) in a distance of 300 feet (91.44 meters) and vehicles without CAB/HVAC in 250 feet (76.2 meters) or less. Perform test in both directions across the testing field and average the speeds. If vehicle does not obtain the desired speed in the specified distance proceed to Step 2. If vehicle obtains the desired speed in the specified distance the performance checks procedure is COMPLETE. Reconnect hydraulic temperature sensor and clear DTC with Digital Wrench.
2. Tighten command lever torsion spring bolt ｼ turn to increase speed. NOTE: If the vehicle does not meet performance specifications after three complete tests contact Bobcat or Polaris Service Troubleshooting for further assistance.
Sorry this is so long, but this is a very difficult process and is why so many problems occur.
Next step is to make the pump squash plate adjustment. This should be made at high idle on jack stands with the squash plate just moving the wheels forward then back slowly until they stop. This adjustment is described in detail elsewhere on the site.
Now make sure the treadle pedal cables are adjusted for the correct free play and the wheels do not move in high idle. While still on the jack stands in high gear the treadle pedal should achieve about 30mph fully depressed forward and about 8mph fully depressed reverse, if not make those adjustments.
Now off the jack stands the HP Commander are made as per the Bobcat Dealer.
FORWARD TRAVEL RPM CHECK (PERFORM LOADED FOR CAB VEHICLES, UNLOADED FOR NON-CAB):
This check verifies the horsepower management system is functional and adjusted correctly for optimal performance. The command torsion spring bolt can be adjusted in quarter increments beyond the baseline setting below to match personal preference or based on accessory loads and vehicle usage.
1. With transmission in HIGH range on level asphalt depress the travel control pedal to the full forward position with a quick fluid motion.
2. The engine RPM at 20 mph (32.2 km/h) should be in the range of 3400-3600 RPM for loaded testing and 3550-3650 RPM for unloaded testing. If engine RPM is not within specifications proceed to steps 3-6. If the horsepower management functionality is within specification, proceed to the FORWARD TRAVEL SPEED CHECK
3. To decrease the engine RPM (increased engine pull down), loosen the command torsion spring bolt nut (Fig.1 Item 6) and tighten command torsion spring bolt (Fig.1 Item 5) ｼ turn.
4. To increase the engine RPM (decreased engine pull down), loosen the command torsion spring bolt nut (Fig.1 Item 6) loosen command torsion spring bolt (Fig.1 Item 5) ｼ turn. Note: This setting can be adjusted to match user preference, if desired. Tightening the spring will result in increased engine pull down/lug and may require more modulation of the travel control pedal when under load. Loosening the spring decrease engine pull down/lug under load.
5. Repeat steps 3 - 5 until the RPM is within specification. If Forward Travel RPM is within specifications proceed to FORWARD TRAVEL SPEED CHECK.
FORWARD TRAVEL SPEED CHECK (PERFORM LOADED FOR CAB VEHICLES, UNLOADED FOR NON-CAB):
This check verifies the horsepower management system is functional and adjusted correctly for optimal performance with a full accessory load. The command torsion spring bolt can be adjusted in half turn increments beyond the baseline setting below to match personal preference or based on accessory loads and vehicle usage. On straight, level asphalt or concrete, mark off a distance of 250 feet (76.2 meters) for non-CAB/HVAC models and 300 feet (91.44 meters) for CAB/HVAC models.
1. With transmission in HIGH range depress the travel control pedal to the full forward position with a quick fluid motion. Vehicles equipped with CAB/HVAC should accelerate from 0-20 mph (0-32 kph) in a distance of 300 feet (91.44 meters) and vehicles without CAB/HVAC in 250 feet (76.2 meters) or less. Perform test in both directions across the testing field and average the speeds. If vehicle does not obtain the desired speed in the specified distance proceed to Step 2. If vehicle obtains the desired speed in the specified distance the performance checks procedure is COMPLETE. Reconnect hydraulic temperature sensor and clear DTC with Digital Wrench.
2. Tighten command lever torsion spring bolt ｼ turn to increase speed. NOTE: If the vehicle does not meet performance specifications after three complete tests contact Bobcat or Polaris Service Troubleshooting for further assistance.
Sorry this is so long, but this is a very difficult process and is why so many problems occur.
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The infamous Command Lever as modified by Interceptor. If you are willing to modulate the treadle pedal yourself, basically letting the treadle pedal return some towards low idle when the engine is about to stall, this is the way to go. You can forget all about the HP Management adjustments above by making Interceptor's Command Lever Modification.
It works by locking the pump's Pintle Lever to the Command Lever. Yes if you mash the pedal to the floor on take off you will stall the engine, I have not found this to trouble me in the least, the modification works wonderfully.
Totally Recommend.
It works by locking the pump's Pintle Lever to the Command Lever. Yes if you mash the pedal to the floor on take off you will stall the engine, I have not found this to trouble me in the least, the modification works wonderfully.
Totally Recommend.
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The Command Lever Mod by Interceptor is the screw in the lower left hand corner of the picture.
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As you can see we are moving beyond what the Dealer can do and into what can be done to deliver more power for inclines and more top end.
If your Brutus is under warranty, the command lever and following modifications will void your warranty.
That said, the quest to realize the true promise of the Brutus concept goes on. We will find the maximum power and speed that can be attained with the components provided.
If your Brutus is under warranty, the command lever and following modifications will void your warranty.
That said, the quest to realize the true promise of the Brutus concept goes on. We will find the maximum power and speed that can be attained with the components provided.
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The next step is fuel. Increasing diesel engine fuel to a point increases power across the RPM range. Increasing RPMs will add horsepower. We will do both. Now I will go make adjustments and report the optimum modifications here.
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How to get that confounded tube off without losing your mind. Use a puller. A trip to the hardware store for 3/8ths - 16 bolts and T-Nuts, please see the photo.
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Now modify the T-Nut flange as in this photo. Notice the arcs ground into them. The Arc size is relative to an 18mm diameter.
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As you can see in this picture how those arcs work. I used a 10mm socket on the acorn nut on the other end and the tube popped right off!
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One full turn counter clockwise and the power is there! Climbed a hill in High about 10-12 mph that would always stall before. Low would only do 6 mph before now it's 11-13 mph. These are on about a 25° incline. Acceleration is much better too. A noticeable quieting of the engine top end and mellowing of the exhaust note has also been realized.
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The picture got lost, tube and puller.
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Max Engine RPMs now set to 4000 with PTO throttle, that's a .5 % increase over spec max, so no biggie there. Still trying to get that with the treadle pedal, now seeing 3750-3800 depending on grade. Top Speed in high almost 35 mph. Pulling moderate grades at 27 mph. The Brutus is actually becoming fun to drive in High! Pulling significant grades in high at 20 mph and serious grades at 10 mph as well all in high! There is more to get with the treadle cable and I am on that next. More Engine rpm produces more pump flow, more flow produces more trans motor speed and we will be trans motor soon.
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The forward throttle cable travel is to short and will not travel far enough at this point to realize engine output improvements at the treadle pedal. Please see throttle cable thread for more.
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Thanks for sharing.
All good information, sure wish that little tube was easier to pull off, ended up using an air saw with no collateral damage. Here is where I screwed up, I marked a line with a sharpie for a reference point (after removing the acorn nut) and loosened the jam nut, I got interrupted for about a half hour and came back to the task at hand and noticed that I had wiped my line clean, Oh no! Is there a starting point with that screw ie. bottoming out and backing it off to the factory spec? I think I may have only turned it out a half to three quarters of a turn but not sure. Once I get that sorted out, I'll complete the Command lever mod. Looks like a 1/4-20 screw? Hats off to you guys doing these mods and sharing your wealth of information since there is not much out there concerning these Brutus's. I've had mine since new, picked up April 2014, it a 2013. Thanks again!
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If you've lost track of the original position of the smoke screw the only way to get it back to original spec is on a test bench at a Yanmar dealer. You're probably safe at one full turn out. It shouldn't be making any black smoke, if it is you should turn the screw back in some.
I've gone a bit further with my command lever mod. I removed the HP spring completely, bored the command lever to a press fit and keyed it to the pintle lever. It really firmed up the pedal feel and had an interesting side effect, it reduced the audible whining noise considerably. I figure the floppy stock command lever setup must have been vibrating and sort of ringing like a bell.
I've gone a bit further with my command lever mod. I removed the HP spring completely, bored the command lever to a press fit and keyed it to the pintle lever. It really firmed up the pedal feel and had an interesting side effect, it reduced the audible whining noise considerably. I figure the floppy stock command lever setup must have been vibrating and sort of ringing like a bell.
I always thought that ringing bell noise was coming from that aluminum heat shield on the exhaust manifold, when I press a finger down on it seem to deaden the ringing a bit. The Smoke Screw.. lol, I played it safe and locked it where I last played with it, no noticeable smoke or power gain but I haven't locked up the command lever yet.
Any chance of a video showing complete process? I know that is a lot to ask but I am new to the forum and to be honest, you lost me. What year is your vehicle? Kohler or Yanmar? Looks like you replaced the stock command lever with an after market, and then modified the fuel system. But I am not sure of what I need to do to get access. Any more info would be appreciated.
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I know this is an older thread, but was wondering if this was for the Yanmar or Kohler engine.
Thanks
Everything that I have seen here matches up with my 2014 Yanmar. I am not sure if it applicable to the newer Kohlers or not. Having followed the procedure in the service manual I was able to make my Yanmar a bit more responsive. It had the misfortune of joining a farm fleet that included a 2010 RZR 800s, completely different animals and I am gradually beginning to accept that.
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