Clogging MMM -- help!

[nh_bota]

Yesterday the MMM on my BX2350 (with bagger) was clogging almost instantly at the lower end of the bagger boot, just outside of the deck. I checked the bagger belts for correct tension -- all ok. When I say instantly, I mean within about 20-30 feet. I was cutting at a length that never even clogged by old Scotts garden tractor. Grass is dry.

However, I did notice that the deck did have a decent amount of build-up underneath, which I promptly cleaned up and then had to put the tractor away (kid duty). I'm eager to try again later today, but wondered if build-up under the deck could be causing such a problem. I've used the MMM/bagger several times since getting the tractor this spring and this is the first problem I've had.

 

[AMR]

I had the same problem in the spring, bagger would clog in 50' of mowing, in fact, I sheared a pin on the internal bagger shaft between the two gear boxes, tough pin to find, I recommend stocking up on a couple. I never ran my BX23 at WOT while mowing last year and never had a problem. This year, however, it has been much wetter and my lawn is much thicker and I also got past 50 hours. I find that if I run the machine at just a tiny hair under WOT I have no clogging issues. In fact, I mowed in a pretty good rain last week, it was the only chance I had, and the grass was pretty tall with no clogs at all.

I looked under the deck when it was clogging in the spring and saw a lot of stuff stuck to it, I too thought that this would lead to clogs. I looked under last week and I saw still a good amount of stuff stuck to it but probably less, I think running at higher RPM keeps the deck cleaner and the bagger from getting clogged. I can't say that stuff stuck to the deck leads to clogs but I wouldn't be surprised if there is a critical mass there somewhere and it does makes sense, but I think that some stuff will always be stuck to the deck.

The only side affect I have seen is that the furthest two bags fill up and the first bag, directly under the discharge, only fills up about 2/3, minor issue.

 

[nh_bota]

AMR, thanks for your quick response. I'm not sure what pin you're referring to, but I'll take a look to see if I can find it and determine if it is sheared (my guess is no, since the impeller is spinning).

Terry

 

[KeithInSpace]

I also have the bagger and have only had the clogging problem in long, wet grass conditions when making a 'full cut'. I mitigate by only cutting a half-deck-width in those conditions. Of course, I have also started mowing more often and that is working quite well. This is my first season with my pride and joy 2230.

Regarding the shear pin: The pin is located on the bagger unit under the little square 3-sided "scatter shield" held in place by the two 10mm nuts on the two sides. If you don't see any nuts or bolts and you only see a hole in the shaft near the bagger unit, you HAVE sheared your pin. I use a 1/4" x 20 x 2-1/2" Grade 5 bolt as the shear pin at the recommendation of my dealership. I use a nylock nut to resist spin-off. I also tried a 2" long bolt, but the 'shoulder' wasn't long enough and the threads aren't as strong in shear as the 'shoulder'. MAKE SURE you get Grade 5, not regular flavor (much too weak) or Grade 8 (too strong...could break internal components. I have sheared 4 bolts since using the Grade 5, so I am 100% certain it is doing its job. The 2-1/2" long bolt in there now has been fine for 3 full cuts...a record for me.

Another thing: If you reach into the impeller housing with the tractor off and can spin the impeller, your pin is sheared. Give it a good tug to make sure. It has fooled me before by the impeller "spinning" when the PTO is engaged, but it is only due to friction from the remaining bit of pin and is too weak to do its job.

And I only mow at WOT. To be honest, it takes all 22 of my HP to run the bagger and 60" deck and I have bogged slightly going up a steep incline. Couldn't imagine running anything less. And I haven't made a big deal of cleaning the deck beyond hitting it with a hose. Chunks happen.

 

[nh_bota]

Where do I find this shear pin? This sounds like the issue I'm having. I have the new bagger version, but I imagine the assembly is very similar.

 

[nh_bota]

Sorry, I overlooked your description of where to find the pin.

 

[nh_bota]

Just called the dealer -- "yup, got ONE in stock." He said the symptoms sound like the shear pin is the culprit.

Looks like I'll need to stock up (as suggested).

Thanks guys... you were a big help. Now I can't wait to get home to see if this is the problem.

 

[Volfandt]

I don't have the Kubota bagger but I do have a pull behind CR bagger and I've had it clog on occasion also.
When I mow I side discharge into several windrows then hookup the CR and go back to pickup the windrows. I've found that it cuts down on the trips to the compost pile and doesn't add much more to my mowing time.
The only drawback is that the windrows can get pretty thick and if I go too fast picking them up, especially when it's alittle wet, it'll clog at the boot. If I go slower I can generally avoid clogging. Sometimes I have to take a smaller bite too. Wet grass plus too high a mowing speed plus running to slow an rpm = clog's.
Course a sheared shear pin will cause it also

Volfandt

 

[KeithInSpace]

Down side to Kubota bagger: Not as simple as a quick twist to detatch or convert to side discharge. Very effective bagger, but you have to live with a few limitations.

Regarding shear pins: I buy them by the bag at Lowes or Home Depot. You get them off the wall in the little sacks 3 at a time...or loose in the "specialty fastener" area...just be careful not to get Grade 8. Grade 5 has three little tick marks 120 degrees apart on the hex head...Grade 8 I think has a triangle on the hex head. Just grab a few sacks. While you're there, pick some up for me. I'm out and keep forgetting.

 

[nh_bota]

It appears that the new version of the bagger doesn't have the shear pin as we've discussed because it's all belt-driven inside the bagger assembly. Maybe Kubota took note of people's shear-pin woes. At any rate, I adjusted the belt tension a little bit more and made sure there was nothing in the chutes. It didn't seem to clog as badly.

BUT... here's the interesting part (at least to me)... I noticed that I had been running the tractor in low speed (turtle speed, as my 4 year olds call it). When I changed to high (rabbit speed), the bagger performance was significantly better -- it seemed the bagger might suck the green off the grass. No clogs for the rest of the mowing -- not even close. Does the low speed draw more torque from the engine, thus allowing the machine to bog down more easily when mowing?

 

[KeithInSpace]

Turtle speed like Low Range? Or turtle speed like Low Engine RPMs. Having the transfer case in high or low range should have no impact. Obviously, low RPMs would kill cutting/bagging performance.

 

[nh_bota]

Yes, low range. I kept the engine RPMs the same -- about 3100.

 

[AMR]

You know, interesting comment on "how fast to mow". I have had the experience that if I mow at WOT but move slowly in low range, like half pedal, the bagger has clogged. The entire time I was thinking that less volume of grass would allow the bagger to work better. I find that if I move at a good rate of speed, like low range, WOT, pedal almost to the floor, the bagger doesn't clog even with the thickest wettest tallest lawn grass. It is neat to hear big old chunks of grass get sucked into the bagger while you are mowing quickly, if I slow down it is like there is not enough grass to push the chuncks up the chute and they get stuck.

 

[nh_bota]

I'm sure, as Keith indicated, that the selected range has no bearing on performance. It seems to me that it's a function of ground speed and RPMs. I must have just made an observation of coincidence. I guess you need to make the judgement based on how dry or wet the grass is, along with its length.

 

[nh_bota]

Ok, now I'm convinced that there must be a design flaw with the new bagging system on the BX. I cut short grass today that has been sitting in 85+ degree heat for 4 days and it still clogged -- not constantly, but in grass that would have been no problem for my old Scotts garden tractor. It's making me wonder how much field testing Kubota did with this new unit. From talking to others and reading posts on this forum, it's apparent that the previous version seems to be a much better performer... I wonder if it has something to do with a different airflow or the fact that this one is belt-driven (rather than driveshaft-driven). I'm going to the dealer tomorrow to speak with them about this. This thing was supposed to make my life a little easier, but it has failed to do so. Love the tractor, but really do not like the bagger.

 

[Dusty]

Hight of the mower deck will effect performance. Also, the amount of build up under the deck will effect performance. I suggest that you make sure that the underneath of the deck is free of any stuck on debris and that the blades are sharp. Also, it won't hurt to give the bottom and chute a spray of silicone lubricant. Same for the connecting hose. The higher the speed of the blades, the more lift of the grass under the deck. Remember that the grass must travel across the width of the deck to the boot to get sucked up. Anything that you can do to reduce the amount of restriction will help the suction. Cutting on a humid day is different than cutting on a dry day. Humidity in the air can and will effect the performance of any bagging system. The moisture content of the grass is another factor. Rich lush grass is heavy with moisture. If you have to cut with only half of the deck width, try cutting with the chute side whenever possible. Keep the RPM's up and the speed down for the best cut and bagger performance. Dusty

 

[nh_bota]

Dusty, thanks for the input. It was definitely humid today. I don't mean to beat up on the design or the quality, but it's quite frustrating considering the thing cost more than my first lawn tractor. Perhaps I should have cooled down some before writing my post.

 

[nh_bota]

I removed the upper hose from the bagger and found that it had comletely rotted at each crease, which could explain a loss of vacuum pressure I suppose. Looks like Kubota chose the wrong material for the hose. My dealer was completely puzzled and shocked, but he's picking up the tractor today and providing me with a loaner... he said it sounds like they might need to work through Kubota on this issue.

 

[c-and-a]

I am having my 2350 delivered tomorrow or Friday (hopefully)...with the 60" MMM and bagger - interesting after reading this thread and speaking with the dealer today, he is puzzled - he received three bagging systems last week and none of them had the chute in them. Hence, I don't know when he plans to deliver my tractor, but I am wondering if Kubota is looking into this...?

Will let you know what happens - but none of this sounds promising.

 

[nh_bota]

I spoke with my dealer yesterday (he has my tractor). He ordered new chutes (top and bottom) for my bagger because the picture he has doesn't look anything like what was delivered with mine. He agreed that the bottom chute doesn't fit the way it should, and the rotted upper chute is just a blatant error and poorly chosen material. The dealer has been great to work with and hopefully Kubota will figure this out. If I don't get a solution soon, I'll probably ask the dealer to send the unit back to Kubota until they've ironed out the kinks.