Kubota B7610 Hydro Behavior

[rswyan]

We have a B2910 that has roughly 1700 hours, bought new from the dealer ... it has done the surging thing for as far back as I can recall ... probably since very shortly after it was new.

I always assumed that it was something inherent in the design.

 

[kcoburn]

rswyn,
Thanks. I was hoping to hear someone say something like that. I ran the tractor 4 hrs yesterday and it didn't surge at all. I'm still going to follow up to get confirmation that the suction strainer was cleaned.

 

[Egon]

Do the engine rpm's increase when ground speed goes up?

 

[kcoburn]

Egon, No, I don't think they RPM's change, though I've never been watching the tach when it happens. The "pitch" of the engine increases slightly and the ground speed increases as though it's found another slightly higher "gear". The change in engine "pitch" is probably because it's working a little harder maintaining the RPMs in this higher "gear".

 

[Egon]

Only other thing I could add are the foot pedals and linkage free and move easily. Will it happen on both smooth and rough terrain? ie can the seat movement effect your pedal contact? If you have cruise control will it do it then?

Just questions; no solutions!

 

[kcoburn]

Egon, Thanks for sticking with me on this. I just greased the hydro pedal pivot before I last used the machine. That may explain why I ran it for 4 hrs without incident. I'm comforted by the "rswyn"s response above stating that he has experienced "surge" since his machine was nearly new. The seat is locked so tight, it won't move when I try. I've never used "cruise" so I don't know if it happens then. I'm going to just use it, as is, unless it starts acting up again.

 

[duber34]

I had a 2004 B7610 for about 9 years and 450hrs. It would surge/ lurch from new when I was trying to maintain a constant ground speed while mowing in high range. I never had the problem when I began to mow in low range. In high I depressed the pedal roughly 1/3 and in low I could just about keep it floored to maintain a ground speed that provided a quality cut. (RPM's constant for both scenarios) I assumed it was me being a bonehead by cutting in high. My reasoning was I wasn't allowing proper hydro flow with the pedal only depressed 1/3.

Regards,
Duber

 

[rswyan]

Do the engine rpm's increase when ground speed goes up?

From what I recall in our case I don't believe that they do.

 

[duber34]

Same here. RPM's stayed constant through the lurch.

Regards,
Duber

 

[chim]

Does it do the jerk when you are headed uphill? I had a B7500 that did, and someone on here explained there was something in the hydro locking up to eliminate some slip. It was normal. That tractor had over 1000 hours on it when I sold it three years ago and never had any problems with the trans.

I don't think the L3200 does it, but after spending 10 years on the B7500 I may have become so accustomed to it / subconsciously expecting it that it doesn't even register if it happens.