Kubota B3350 tractor regeneration problems

[skyhook]

Don't assume anything Other than the DPF problem, I like my 3350. But if I was buying one again, I would ask a hundred questions about that tier IV system and make absolutely sure the dealer was aware of the service bulletins and get documented proof that the updated system was on the machine.

Now if I could get the same tractor without all of that junk - that would be even better.

well said., for that kind of money, so would I.

 

[s219]

The only difference I can see between the two models is that the 33 hp has way more torque and is a bit smoother because of the 4 cylinders.

Actually, the three-cylinder engine will be smoother. Four-cylinders are not as balanced as a three and vibrate more. This was noticeable in past Kubota B models with the four-cylinder (B3200, B3300) compared to the three-cylinder models (B2620, 2920).

 

[sixdogs]

Actually, the three-cylinder engine will be smoother. Four-cylinders are not as balanced as a three and vibrate more. This was noticeable in past Kubota B models with the four-cylinder (B3200, B3300) compared to the three-cylinder models (B2620, 2920).

How can three cylinders be more balanced than four? I have no idea but it doesn't sound logical.

 

[kuboman]

How can three cylinders be more balanced than four? I have no idea but it doesn't sound logical.

Because of the firing order of a three cylinder you have more even power strokes. 3's are definitely smoother than 4's unless you have
balancing shafts which the smaller Kubota 4 cylinders do not have.

 

[sandyc]

I can't speak to firing order or any of that stuff but in my old opinion the four seems to shake less. Of course the seat on the 3350 is a lot more comfortable.

 

[herringchoker]

The way I think of it is this:
In a 4-stroke cycle, each cylinder fires every 2 revolutions or 720* rotation of the crankshaft. With the cylinders firing evenly in a 4-cylinder engine, that means one of the cylinders fires every 180* of crankshaft rotation (720 / 4 = 180), which puts all of the crank throws in the same plane and all the pistons are changing travel direction at the same time. With 3 cylinders, one of them fires every 240* (720 / 3 = 240), so the crank throws are not all in the same plane and the pistons are changing direction at different times - smoother than all jumping at once.

 

[sixdogs]

Thank you very much on the three cylinder info. I had no idea but it does make sense and changes the way I think about three cylinders.

 

[s219]

It's about balance and harmonics. Comparing all the factors, the three is going to be smoother. There is a good description comparing three- and four-cylinder configurations here:

Engine balance - Wikipedia, the free encyclopedia

 

[abcuster]

So why is it that no engine specs can be found for the B2650 and B3350? No hits at all on Google search. Still looking for fuel consumption data for these two models. Any inside Kubota data available?

 

[Beauly]

Ok, just reading through this thread. Bought new B3350SU in Dec, used it a little that month, then the snow started and so I started using it with the snow blower. Early Jan, 11.2 hours, it tried to do a regen as I was snow blowing. No luck, forced a parked regen, that failed, I tried it 3 times. My dealer towed it away. The snow kept coming. Dealer planned to replace the reformer, as described in service bulletin, took a week for reformer part to come in. Two weeks later, and many more snows, I got the tractor back. Used it only for snow blowing since, and a little work around the yard recently spring clean up, no regens since getting it back from dealer. Just this weekend, it called for a regen. No luck, the auto did not work, and then red blinking light and beeping and parked regen light. So I tried a parked regen, it did not complete, tried it twice more, no luck. Called dealer on Sat, they are going to call me today, and no doubt take the tractor back to the shop.

Sound familiar?

Thoughts?