BX-25D throttle lever & hill ascent

[emocwoh]

I have a fairly new Kubota BX-25D which has two problems that the instruction manual doesn't seem to cover. Help appreciated.

First, the throttle lever does not stay in position, but always goes back to a low level. This is irritating, esp. when digging. Any suggestions on how it cab be adjusted to stay in place?

Also, it seems that the engine stops when trying to climb hills. Admittedly, my plot is hilly and I'm probably outside of the recommended operating range. But, does the tractor actually register this and shuts down as a precaution? Or is there something else going on? (I have plenty of fuel in the tank)

 

[OzTinkerer]

Hi and welcome,
I'm new here too but perhaps I can offer some suggestions. Typically throttle levers will have a spring-loaded friction disc to hold them in the set position. This is usually at the pivot point of the main lever but could possibly be at an intermediate linkage pivot between the main lever and the injection pump. See if you can find this and if it's possible to add more tension to the spring to increase the friction. Also, a PO may have been a little too generous with WD40 etc. around the friction disc. It it looks oily/slippery, you might be able to loosen-off the tension and clean the disc/friction material with some brake cleaner spray, then re-tension.
With the engine stopping on hills, a lot of the little Kubotas are fitted with mid-mount mower decks. As such, they may be fitted with safety switches under the seat, to stop the engine if the operator leaves the seat with the mid-mount PTO engaged (even if there's no mower deck fitted)? And perhaps when climbing steeply up hill, you may lean forward enough to operate the seat switch? Just a thought.
Ian

 

[Gary Fowler]

When you say the engine stops, does it just turn off or stall down? Stalling down is caused by too much forward pressure on the HST pedal. As the engine lugs down, just back off the HST pedal to go slower which is like shifting to a lower gear on a standard transmission. Many first time users think that if the tractor is slowing down, push harder on the pedal but just the opposite is true.

 

[radioman]

on the bx -- there is a screw for adjusting the throttle cable. if it too loose it will move on its own. open the hood and find the throttle cable -- it pretty much right there on top. follow it back to console and you will see a clamp like with screw. give the screw a little twist ..testing the throttle movement.
as for the engine shutting of -- i am curious -- are you close to the rated rpms or at least above 2800? it should not shut off n middle of climbing the hill . if it shuts off going down the hill -- i am not sure if you somehow have the older seat that makes you slide off as the safety switches kicking in as you "sliding off the seat" . we need a bit more info from you as when it actually shuts off.up ? down the hill? low rpms? have tank always more then half while on the hill? rpms when it shuts off? was it high when you start then goes really low rpms? if the rpms really falls - either the fuel filters are somehow plugging up already or something wrong with fuel delivery system.

 

[emocwoh]

on the bx -- there is a screw for adjusting the throttle cable. if it too loose it will move on its own. open the hood and find the throttle cable -- it pretty much right there on top. follow it back to console and you will see a clamp like with screw. give the screw a little twist ..testing the throttle movement.
as for the engine shutting of -- i am curious -- are you close to the rated rpms or at least above 2800? it should not shut off n middle of climbing the hill . if it shuts off going down the hill -- i am not sure if you somehow have the older seat that makes you slide off as the safety switches kicking in as you "sliding off the seat" . we need a bit more info from you as when it actually shuts off.up ? down the hill? low rpms? have tank always more then half while on the hill? rpms when it shuts off? was it high when you start then goes really low rpms? if the rpms really falls - either the fuel filters are somehow plugging up already or something wrong with fuel delivery system.

Thank you for your considerate reply. The throttle issue is now fixed. I'll also monitor closely the RPM when shutting down. To me it feels like it shuts down automatically when getting above a certain angle, but less pressure on the seat may be a more likely option.

 

[emocwoh]

When you say the engine stops, does it just turn off or stall down? Stalling down is caused by too much forward pressure on the HST pedal. As the engine lugs down, just back off the HST pedal to go slower which is like shifting to a lower gear on a standard transmission. Many first time users think that if the tractor is slowing down, push harder on the pedal but just the opposite is true.

Thanks, this is an interesting hypothesis. I'll try this the next time.

 

[Grandad4]

1

Thanks, this is an interesting hypothesis. I'll try this the next time.

Gary comments are valid, not hypothesis, regarding how HST's operate, but that may or may not be the issue for you. Remember it's a variable gear shift, not a throttle, so flooring it is like putting your stick shift car in fifth gear to go up a steep hill, when you really wanted to downshift to second. Engine will bog down and maybe even stall. Many discussions about this topic here. If your grade is that steep, consider dropping into low range.

Some other hypotheses re. what your engine is doing: If engine immediately and abruptly dies without bogging down, it's more likely the seat safety switch is the culprit. If it sputters and then dies, could be a fuel starvation issue. Just some additional theories to ponder. Good luck sorting it out!

 

[check]

1 Gary comments are valid, not hypothesis, regarding how HST's operate, but that may or may not be the issue for you. Remember it's a variable gear shift, not a throttle, so flooring it is like putting your stick shift car in fifth gear to go up a steep hill, when you really wanted to downshift to second. Engine will bog down and maybe even stall. Many discussions about this topic here. If your grade is that steep, consider dropping into low range. Some other hypotheses re. what your engine is doing: If engine immediately and abruptly dies without bogging down, it's more likely the seat safety switch is the culprit. If it sputters and then dies, could be a fuel starvation issue. Just some additional theories to ponder. Good luck sorting it out!

So if I am going full throttle with the go pedal all the way down up a hill in high range, and it starts to slow down and mighr not make it, I should take my foot OFF the pedal a bit?

 

[frugalangler]

So if I am going full throttle with the go pedal all the way down up a hill in high range, and it starts to slow down and mighr not make it, I should take my foot OFF the pedal a bit?

YES!, and/or shift into low range! Like said before, it won't climb a hill in high gear, which is equivalent to the foot pedal all the way down. High range is generally for flat land transport w/ no load, for hills and implements you should/need to be in low range.

 

[Grandad4]

Yes. Remember the hand throttle is what controls engine rpm, not the foot pedal. The foot pedal adjusts the "gear ratio", although it's doing it hydraulically. More pedal = faster speed, less pulling power... less pedal = slower speed, more pulling power.