Lowering the idle on a BX23S

DustyRusty

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2020 BX23S, BX2822 Snowblower, Curtis Deluxe Cab,
Nov 8, 2015
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My BX23S idles between 1400-1450, and it makes driving more difficult, since it wants to take off running, no matter how softly I depress the pedal. It also stops abruptly when you let off of the pedal. Is it possible to drop the idle down to about 800 RPM? What can be done about the abrupt stopping when I let off of the pedal?
thanks
 

lugbolt

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ZG127S-54
Oct 15, 2015
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entirely possible but DEFINITELY not recommended. That engine shakes so badly at sub 1100 rpm that the engine becomes invisible, a gray blur, from the vibration. Also your HST and hydrualic pump will likely not even work at that low of an RPM. They're bad enough at 1400. The abrupt stop when you let off may be solved by two different things. One, let off slowly. Two, perhaps the little damper on the pedal linkage may be failing. It has a damper that is supposed to slow the rate of which the pedal can move. Looks like a hood or trunk strut from a car but shorter.
 
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imnukensc

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BX2380
Sep 10, 2015
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It's working exactly like its supposed to work. Many people complain about their BX (of whatever flavor) not stopping when they let their foot off the pedal. There are adjustments that can be made to the linkage without changing the idle.
 
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GreensvilleJay

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BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
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ok, silly question, but have you cleaned and greased the foot pedal mechanics under that 'flap in the rubber flooring'.....?

I've got about 940 hrs on my 4 year old and it doesn't act the way you describe....
 

85Hokie

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AS the other 2 have stated clearly ......... IT is that way for a reason - DO not change it !

now lets look at the other part of the problem. The damper - as Lugbolt mentioned, this is more than likely your problem.

My BX2370 is smooth as silk, but my 16 year old BX1850 will snap your neck off IF you let off the reverse pedal too quickly.

Check all the linkages - how many hours on your machine btw?
 

GeoHorn

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M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
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Dusty, That engine (D902) is in my RTV and when I bought it…it vibrated like HELL… the entire vehicle rattled to drive you nuts!
I read the manual and discovered it was supposed to idle high… Apparently the original owner (it had only a few hours on it) had lowered it because they thought diesels were supposed to idle slow.

The sealed-wire idle screw had obviously been tinkered with. I increased the idle to where it ran smoothly…. (no tachometer on this machine)…which sounds to me to be ”about” 1200-1400…. and it now runs smooth and puts-out power!

I think others have offered good advice as well… you might read the OM to see what it says.

As for stopping abruptly… Yes, it took a bit of “getting used to”… to let up gently in anticipation of coming to a stop. Other RTV owners have installed “coast valves” …some sort of mod that is sold aftermarket…costs hundreds and changes the engine-braking characteristics… Then they complain about having to ride-the-brakes and brake burn-out fears when going down-hill.

It’s a lot cheaper and more useful to modify your own behavior and expectations. ;)

Hope this helps.
 

Henro

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B2910, BX2200, KX41-2V mini Ex.
May 24, 2019
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I solved this issue over time by NOT greasing the pedal assembly at all. Now after 19 years I do not have an issue with my BX2200...

It used to act like dustyrusty's does now...I learned to live with it and gradually transitioned to the way it is now... :)
 

lmichael

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Kubota G2160
Apr 23, 2021
525
209
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Rockford IL area
Wouldn't there be "harmonics"? Affecting how roughly or not the engine idles? IOW if a smooth idle is obtained at say 1100 could it not possibly run in multiples up or down from the there? IDK, simply tossing it out there. I have seen this phenomenon on gasoline engines. Especially on some V6 engines as they tend to have an inherent "wobble" to them
 

GreensvilleJay

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BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
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hmm, is a V6 really two, 3 cylinder engines ???
If so I consider it to be a '3 phase' engine NOT a '6 phase' engine.
A true 6 phase engine would run very smooth, one bang every 60 degree of crankshaft rotation....
 

lmichael

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Kubota G2160
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Actually they don't. Especially the old 90deg V6 as was the old original Buick 231 V6 and the Chevy 4.3 which as simply a 305 with 2 cylinders cut off. Those engines were real rocky idlers
 

dlsmith

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BX2230, LA211
Nov 15, 2018
1,197
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hmm, is a V6 really two, 3 cylinder engines ???
If so I consider it to be a '3 phase' engine NOT a '6 phase' engine.
A true 6 phase engine would run very smooth, one bang every 60 degree of crankshaft rotation....
A six cylinder four stroke engine will generate a power pulse every 120° of rotation.
Takes two revolutions to complete a cycle. 720° / 6 = 120°.
 

lugbolt

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ZG127S-54
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hmm, is a V6 really two, 3 cylinder engines ???
If so I consider it to be a '3 phase' engine NOT a '6 phase' engine.
A true 6 phase engine would run very smooth, one bang every 60 degree of crankshaft rotation....
V6's are 120 deg split (even-fire V6's that is). 720/6=120. Oddfire V6's are just odd. One cylinder fires, then 90 deg later another, then 150 deg of crankshaft rotation another. 90-150-90-150-90-150. Real strong bottom end design but they sound odd, they run odd, and they'll throw you for a loop unless you know. 3 cyl engine, vibrates horribly at certain speeds, and being diesel is wayyyy worse. As I said earlier the kubota in this post, if idled down that low, the engine will disappear into a blur because of vibration. Actually the person trying to adjust the little screw? Won't be able to, first you won't be able to see the screw and secondly won't be able to get a tool on it. Trust me I've tried. When I was younger and first getting into the kubota business another tech said hey watch this (famous last words of a redneck?). He moves the stop lever just right so that the idle speed would drop way down. At a certain point, roughly 700 RPM (on a BX nonetheless), the engine turns into a blur. The entire machine starts vibrating back and forth. 3 cyl engines in general will have a weird rocking motion about them, adn V6's generally do too if they are not counterbalanced-which the majority of them are. The old Dauntless Buick was not, and even the even-firing version (they had odd-fire and even fire versions) were called "shakers" for a reason. The 4.3L Chevy V6, they shook too, until they finally started putting balance shafts in em. Mopar 3.9's same, I think a lot of those were odd-fire V6's. May be wrong on the mopars, I haven't dealt too much with em. Ford's have had balance shafts in all their 90 deg V6's but I have not been into their 60 deg engines. Almost all modern V6's are 60 deg bank angle now, for the main reason that they fit better in front drive vehicles. Buick/Dauntless 3.8 (aka 3800), 3300 Buicks, Chevy 3.8L (229"), Chevy 200 (3.3 I think), Ford 3.8 and 3.9L (Essex V6), and the Mopar 3.9's are all 90 degree. The Ford V6's are almost identical copies of the Buick's. Ford admitted to it as I understand. They were decent engines, especially the later split ports and the 3.9L--oh and I almost forgot the 4.2L version used in pickups. Those are also 90 deg bank. Ideal bank angle of the V6 is 120 deg, but that makes for a really wide engine and to my knowledge I can't remember seeing any mass produced. They were (are?) used in racing though. Indycar?

V6's are two inline-3's but they are out of phase, but not out of phase enough to cancel out vibration. That's where the Inline 6 comes in. Two I-3's, one in front of the other...they both vibrate but they vibrate exactly opposite of each other, canceling any felt vibration out.

A lot of new tech coming out in the last 10 years or so on engines. Case in point the 270 deg parallel twin cylinder. Great design except it needs a counterbalancer. Sounds wonderful, runs very very smooth, makes good power AND torque to boot. Polaris uses them on the 925 turbo Rzr, the 850 and 1000 sportsman, Yamaha uses them on the MT-07 motorcycle and 2 or 3 side-by-side atv's, Honda on the Talon and 1000 Pioneer, among many others. I find this stuff fun to think about.
 
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lmichael

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Kubota G2160
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I never heard "dauntless" applied to the ol Buick V6. There was another GM V6 and oh boy that thing could shake. It was the 292 truck engine. They were absolute tanks. Cylinder heads were heavier than any other head I tried to pick up. That includes old big block V8s, even up to the mighty 500 cu in Caddy V8. Only head I ever tried to pick up that was as heavy was a straight 6
 

dlsmith

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Odd fire V6s are usually based on a V8 block with two cylinders lopped off. But by using split rod journals that have a 30° spread, you can get an even fire V6. Other even fire V6s have a 60° bank angle.
 
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lmichael

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Kubota G2160
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Odd fire V6s are usually based on a V8 block with two cylinders lopped off. But by using split rod journals that have a 30° spread, you can get an even fire V6. Other even fire V6s have a 60° bank angle.
Yeah the engines I named were based originally off V8 cousins
 

lugbolt

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ZG127S-54
Oct 15, 2015
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really the only reason the V6 is even around is because of packaging. It's a terrible design in a lot of ways that, in most cases, be replaced by an inline 4 or 6 that accomplishes the same job with much better and less expensive overall costs.
 
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