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Discussion Starter · #1 ·
Just curious, I'll bet those of you who have a good low idle per spec 1250 RPM have no more than 3400RPM high idle and conversely if you have a good high idle 3750 RPM your low idle is about 1900 RPM.

I would have never believed my stock Brutus could make 30 MPH on level ground. It did today because I made sure I had the spec maximum high idle RPM of 3750 when I floored on the forward pedal.

Here is the deal, the throttle cable at the fuel control stroke is too short to give you both the proper low and high idle. It is a good thing the cable mount is not solid. It can easily be tweaked by bending it closer for better low idle or pulled farther away from the fuel control for a better high idle. Because that cable is short of the needed stroke, it does not give you both low and high idle correctly.

My engine throttle independent of the cable gives me exactly 1250 low and 3750 high idle as it came from the factory. Now the only place you will get your 27 HP and max torque is at 3750 RPM.

More Later.
 

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Discussion Starter · #2 ·
Well.. I have 3750 RPM with the PTO throttle, but was unable to get that with the forward pedal, only 3650 RPM there and 3200 RPM with the reverse pedal. Low idle is 1750 RPM. Still managed 30 MPH on level road.

Uphill here is a steep proposition with sections of road at a 45 degree incline. The Brutus managed 10 MPH up those in low gear.

I have the modified command lever per Interceptor's picture in place. While adjusting for forward RPM I noticed the plate flexing at the cable adjustment location. My assumption is that cable is too short of travel as well.

That's my findings and two full days of chasing adjustments trying to get the horse power and torque the engine has to give if only the control cables had the travel to get it.
 

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It's been a while since I've been under the bed, but I don't recall having any trouble getting the required range out of the cables. Mine idles at 900 and tops out at 3800 using the pedal.
 

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Discussion Starter · #5 ·
I have been on a mission to straighten out the power problems with my 2013 Brutus. By changing the throttle hole used by the cable at the engine I was to get both spec low and high idle, some tweaking of the cable mounting bracket was also needed.
 

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Discussion Starter · #7 ·
The reason for the low idle setting @ 1350+/-100rpm is to maintain adequate alternator output for electrical accessory loads.
 

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Discussion Starter · #8 ·
The ah ha moment has arrived. I now know why each vehicle has a dead set top treadle pedal RPM no matter what you do. Interested? Check this picture from underneath the forward section of the treadle pedal. Polaris machined a flat to rest on the frame cross member. What ever the tolerance stack up is, is what you get. Mine was 3743 RPM. Yes the treadle pedal is coming out for an adjustment of that contact point.
 

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Discussion Starter · #9 ·
After hours of work there is just no getting around a forward throttle cable with only 3/4's of an inch of travel. The Treadle Pedal cable offers just over 2 inches of travel, what a tease... Even the reverse throttle cable has more travel. Conclusion, no further improvement will be had until a satisfactory throttle cable assembly is in hand. Now I'm looking for a good custom cable maker.

The Treadle Pedal forward modification above did help achieve more stroke. That ended up helping reverse travel because the forward throttle cable is so short.
 

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Discussion Starter · #10 ·
One thing to consider, the command lever has just over an inch of travel between the forward throttle cable mounting points. Yours may be different, but that means I have never had full forward pump flow to the trans motor. In this case flow translates into more speed.
 

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The Ranger throttle cables have a rubber cushion on the pedal end to prevent stretching or breaking the cable in case of an over travel condition. I know a lot of guys have had problems with the rubber compressing prematurely and not allowing full throttle. Perhaps something similar here?
 

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Discussion Starter · #12 ·
Not that I can see, the only rubber is gaiters to keep debris out.

There is a custom cable and a Treadle Pedal modification to be designed. Yes I will share if it does any good, you will need a good mig welder operator to do it.
 

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I recently had the throttle cable replaced because the end wore off and broke. Since the dealer replaced the cable, my Brutus is super slow and only achieves about 2200 rpm in forward but goes like a bat out of haedes in reverse, reaching 3700rpm. Could they have installed the cable wrong? Before it was replaced it ran great!
 

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I recently had the throttle cable replaced because the end wore off and broke. Since the dealer replaced the cable, my Brutus is super slow and only achieves about 2200 rpm in forward but goes like a bat out of haedes in reverse, reaching 3700rpm. Could they have installed the cable wrong? Before it was replaced it ran great!
It most likely just needs to be adjusted.
 
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