I bumped my throttle-limit up to 2750rpm this last weekend, as measured by an optical RPM gauge. The gauge on the dash was pretty darn close.
Based on the dyno sheet from the 1703 as 'timed' for the L2501, I didn't expect much difference, but wow, big difference from my perspective. I generally only run ~1800-1900 RPM's, but when I needed the power, I was running it wide open before and it still just seemed a little light on grunt. Now if I want the power, if I set the no load rpm's around 2550-2600, under load it pulls down to ~2450 and feels A LOT stronger. The 'M' gear on the HST becomes much more usable for travel as well. I expected H to become useless at WOT, given the rpm increase also driving up the ground speed, but dang if this thing does get up to ~15mph faster than it got up to ~12mph before.
I know folks are really divided on any mods like this, and if I was running this thing WOT on a construction site all day I'd probably expect a small reduction in usable lifespan, but I'm a homeowner and this thing will probably long outlast me, even if I set the revs to 3k, turbo'd it, and bumped timing past spec.
If you're reading this years later, and want to know it it 'blew up', feel free to ask me
The only 3-pt implement I run is a 64" snowblower. I look forward to trying it with a little more revs next winter. Yeh, I'll be over the rated PTO speed, but the SB1064 seems to turn slower then the mid-mount PTO driven blower I had on the front of my BX anyway. My guess is if I set no-load ~2500 and let it pull down to ~2300 by modulating my speed into the snow it'll probably do great.
If you want to try this yourself, it's this easy:
1. open hood
2. remove the black plastic cover that sits just under hood level on the loader-valve side of the tractor (3 bolts)
3. move the throttle control from the dash and watch which bolt the linkage stops on when set to wide-open throttle.
4. once you identify the right bolt, unwind and remove the safety wire from the bolt head. you don't need to cut it, it's just wrapped around
5. loosen the stop-nut and back the bolt out a half inch or so.
6. start the tractor and SLOWLY increase the RPM's with the throttle until you reach the desired RPM you want it to stop at. If it still doesn't get as high as you want, it may still be hitting the bolt. Just back it out a little further. Remember the dash gauge doesn't show actual RPM's immediately. You want to raise the throttle very slowly to avoid over-revving.
7. once at the desired high-rpm (I wouldn't go above 2800), slowly turn the bolt back in until it contacts the throttle linkage, and tighten the stop-nut.
8. back off the throttle and then go back to WOT, and re-confirm the bolt is stopping it at the rpm you want before buttoning it all back up. I re-installed my safety wire, just for completeness.
9. enjoy the extra power
A word of caution: This bolt is painted *after* being set by Kubota at the factory. After adjusting it, you can clearly see that it's been adjusted. If you're under warranty, I wouldn't give Kubota any reason to deny a claim. Just wait till the warranty is out.
Based on the dyno sheet from the 1703 as 'timed' for the L2501, I didn't expect much difference, but wow, big difference from my perspective. I generally only run ~1800-1900 RPM's, but when I needed the power, I was running it wide open before and it still just seemed a little light on grunt. Now if I want the power, if I set the no load rpm's around 2550-2600, under load it pulls down to ~2450 and feels A LOT stronger. The 'M' gear on the HST becomes much more usable for travel as well. I expected H to become useless at WOT, given the rpm increase also driving up the ground speed, but dang if this thing does get up to ~15mph faster than it got up to ~12mph before.
I know folks are really divided on any mods like this, and if I was running this thing WOT on a construction site all day I'd probably expect a small reduction in usable lifespan, but I'm a homeowner and this thing will probably long outlast me, even if I set the revs to 3k, turbo'd it, and bumped timing past spec.
If you're reading this years later, and want to know it it 'blew up', feel free to ask me
The only 3-pt implement I run is a 64" snowblower. I look forward to trying it with a little more revs next winter. Yeh, I'll be over the rated PTO speed, but the SB1064 seems to turn slower then the mid-mount PTO driven blower I had on the front of my BX anyway. My guess is if I set no-load ~2500 and let it pull down to ~2300 by modulating my speed into the snow it'll probably do great.
If you want to try this yourself, it's this easy:
1. open hood
2. remove the black plastic cover that sits just under hood level on the loader-valve side of the tractor (3 bolts)
3. move the throttle control from the dash and watch which bolt the linkage stops on when set to wide-open throttle.
4. once you identify the right bolt, unwind and remove the safety wire from the bolt head. you don't need to cut it, it's just wrapped around
5. loosen the stop-nut and back the bolt out a half inch or so.
6. start the tractor and SLOWLY increase the RPM's with the throttle until you reach the desired RPM you want it to stop at. If it still doesn't get as high as you want, it may still be hitting the bolt. Just back it out a little further. Remember the dash gauge doesn't show actual RPM's immediately. You want to raise the throttle very slowly to avoid over-revving.
7. once at the desired high-rpm (I wouldn't go above 2800), slowly turn the bolt back in until it contacts the throttle linkage, and tighten the stop-nut.
8. back off the throttle and then go back to WOT, and re-confirm the bolt is stopping it at the rpm you want before buttoning it all back up. I re-installed my safety wire, just for completeness.
9. enjoy the extra power
A word of caution: This bolt is painted *after* being set by Kubota at the factory. After adjusting it, you can clearly see that it's been adjusted. If you're under warranty, I wouldn't give Kubota any reason to deny a claim. Just wait till the warranty is out.
here are some teaser photos. The exhaust is not done and the adapters I made still need some trimming and I will be ceramic coating all 304ss hot parts. Check it out!!
