Kubota B2650 and B3350 info and hints

[bumperm]

Very cool...I'd like to go full LED eventually with mine.

I thought about that too, but the LED's are *very* bright . . . they don't have any cut-off, so oncoming traffic will be blinded if the cab lights are left on. When snow blowing at night and it's still snowing, even the halogen lights woud probably be too much due to the snow reflection. The LEDs would blind you for sure.

bumper

 

[2010drive]

210drive,

When I first start my B3350, even though I use the glow plugs for the correct amount of time for the temperature (2-3 seconds as it's stored warm around 60 F), the engine starts within a second or two of cranking. But then it doesn't light off and run smoothly on all 4. Rather it misses and chugs along for a few seconds before it smooths out. It does this to a lesser extent even if the engine is already warm. Does your's behave in the same manner?

I've had 3 Kubotas before this one, so I'm familiar with the starting "drill" and none behaved this way. Just wondering if this is normal and maybe due to the DPF?

thanks for your input,

9.5 hours on the B3350 now!

bumper

Bumper,

I started mine up today and noticed it did the same thing. 40F, I primed for 5 seconds started at about half throttle (like the manual says) it chugged along right around 700RPM for 11 seconds before going up to 1300RPM mine was at 2.2 hours when this was done.

 

[bumperm]

201drive,

Most helpful . . . thks for the report!

Okay, here's what I think is going on. My limited understanding is that Kubota added the turbocharger on the 3350 to make up for the back pressure (restriction) caused by the DPF. So far so good, and I appreciate the turbo due to the altitude where I live (part of the reason I got the B3350 over the B2650). But, that turbo charger doesn't come up to speed right away, "turbo lag". This means the engine is starting against all that extra exhaust back pressure . . . this is doubtless causing a rich mixture condition due to the restricted air throughput until the turbo spools up. At least that's my guess. Make sense?

This is also probably the reason they suggest half throttle for starting . . . this, to get the turbo spinning and providing boost ASAP.

bumper

 

[2010drive]

Makes sense to me:thumbsup:

 

[bumperm]

There is one more thing that's not in the manual, but comes from aviation turbocharged engines of which I'm a little more familiar. Small turbos have sleeve bearings. To prevent oil coking due to the heat soaked turbo during shutdown, it's common practice to bring the engine speed down to an idle for 30 seconds or so to give the turbo bearings a chance to cool down. During this idle phase, the exhaust temperature is reduced while pressurized oil continues to carry heat away form the bearings, dropping the temps enough to avoid coking.

Not sure if this is applicable to our little turbo diesel, but that's the procedure I'm going to use until I learn otherwise.

bumper

 

[2010drive]

When you say down to idle how many RPM'S are we talking? Push the lever all the way down? (or up for that matter)

 

[bumperm]

Low idle, throttle lever up. Though if you've been operating at or below 1500 or 1600 rpm for several minutes, the turbo should be fine with an immediate shut down. In an aircraft, taxiing in is really good enough for the cool down. The idea is not to be running full throttle and turn off the key (worst case), or being at full throttle, decrease to idle and shut off the key with no delay (almost as bad as worst case).

It's just conjecture on my part that this is applicable to the B3350's turbo. Costs nothing to treat it nice though.

I asked dealer today if he had any idea of a range of hours one might expect before regeneration of the PDF is needed. He didn't. Of course it'll be variable, based on how the tractor is operated. The DPF itself has a long expected life - - something on the order of 4,000 hours I read somewhere. Good thing, a new one costs $2500. The DPF may be a bit of a hassle, but it is nice to start the trator and not have a billowing cloud of black smoke in the garage. Heck, I haven't seen any exhaust color at all on my 50.

bumper

 

[Toolguy]

My B3030 starts best with the throttle closed. If I open the throttle part way like the manual suggests it spits an sputters for a few seconds. With the throttle closed it starts and run smooth almost immediately.

 

[bumperm]

My B3030 starts best with the throttle closed. If I open the throttle part way like the manual suggests it spits an sputters for a few seconds. With the throttle closed it starts and run smooth almost immediately.

Toolguy,

No dispute . . . the B3350 is a different animal due to the exhaust restricting DPF (diesel particulate filter) and the turbocharger. Thus start proceedure is a little different than most other CUTs. The three other small Kubotas I've owned, including a BX24 I still have at another location, all start as you state.

The B3350 will start with the throttle closed too, at least in the moderate temperatures I've experiences so far - - however, it'll take longer to "smooth out" than when following the Owners Manual advice to use half throttle.

bumper

 

[Toolguy]

I love my simple, old school B3030 even more now!