F3990 Review

[SPaulsen]

After much research for a replacement mower (2003 KubotaG2160R48S DirectShoot) and with a big thanks to JohnThomas' posts and experience, I made the decision to purchase a 2019 F3990 in Dec 2019. I have used the machine for a little over 100 hrs. I have about 12 acres of grass. The terrain is flat, hilly etc....I opted for the 72" rear discharge deck. I have experienced zero complaints and actually the machine has cut my mowing time from 12 hrs to 7 hrs due to its maneuverability. It climbs like a goat on steep hills with power to spare. The mower is stable and provides confidence on uneven ground. My initial concern was the tier 4 emissions...I use the mower at full throttle while mowing and the only low rpm is during warm up and cool down. Regen is consistent every 9 hrs for about 23 mins during mowing. I have not had to do a "parked regen" to date. In regard to side or rear discharge mowing deck opinions from various folks...My only complaint on rear discharge is that the lower side of the mower sucks the clippings around the mower...I just blow the mower off after each use. My preference is still the rear discharge. I would have liked a grass catcher attachment but for $4000 it wasn't worth the cost or the added bulk of the machine which meant opting for a side discharge deck...I use a 52" lawn sweeper to tow if I need to pick up leaves which is only about $350. I was able to retire/sell my LandPride 72" rear discharge grooming mower for the larger areas which saves working hours off my Kubota L45 TLB. Thanks again to everyone for their posts and experiences...it really helped with the decision making process...No machine is perfect, it comes down to what you need it to do and what you can compromise on.

 

[jcummins]

That's great I'm glad it's working out for you. I have an f3680 and my research on the f3990 at the time I bought this machine is that it's not a good cold climate machine because of emissions issues. You're wise in always using Full Throttle on that machine I think the emissions are far better managed when you run the motor that way.

 

[RickB]

You are doing better than most. Those machines are an emissions train wreck more often than not.
I hope you have continued success.

 

[628pm]

Great that it is working for you, i have the little brother F2690 with 72 inch mower and mulching kit.

 

[Hay Dude]

I like hearing it climbs hills well and the rear discharge deck is liked. I still can’t believe it doesn’t blow grass clippings in the operators face.
I really want a 3680 pre emissions unit.

 

[SPaulsen]

Luckily I don't get any clippings blown at me...I would find that most irritating as everyone else would.. I do get clippings toward the air vents of the engine housing (dry grass). I have to occasionally reach around and wipe the vents while mowing to keep the area clear. The inside area of the motor stay relatively clean.

 

[SPaulsen]

I was very close to selecting the F2690 but given some the hills and my "larger" body, I thought I may need more power....probably some overkill on my part...I did buy the mulching kit, but did not attach it yet. My grass grows very fast during the spring (4-5") a week. Still deciding on if or when to install it.

 

[SPaulsen]

You are doing better than most. Those machines are an emissions train wreck more often than not.
I hope you have continued success.

The Tier 4 emissions were a big concern for me as well...My other equipment does not have them. I have a 2013 L45 and I will never replace it because of that.. I think the emissions are more cost and aggravation than good. I have read the horror stories on the forum.

 

[JOHNTHOMAS]

The Tier 4 emissions were a big concern for me as well...My other equipment does not have them. I have a 2013 L45 and I will never replace it because of that.. I think the emissions are more cost and aggravation than good. I have read the horror stories on the forum.

I have a L3901 and never know when it regens unless I smell it. I do quick mid throttle warm up and then set tach on orange dot on tach and keep it there until I turn the machine off and never an issue with 170 hours. I'm not hearing of any issues with Kubota except for the L33xx back a few years ago. I mow full throttle on all Fs and the ZD1211 which shows obvious difference in cut quality vs less than full throttle. Rear discharge is for not getting grass in the face like side discharge unless the side discharge has a restricted mulching kit like I put on all side discharge decks which I only have when I can't get a rear discharge.
I have a electric powered leaf blower on my front porch and after mowing with ZD and F my Grandson and I blow them off and occasionally leave them out in the rain with hoods up for washing the dust off. Grandson gets to mowers before me and now he always picks the F which never gets stuck like the Z and never does wild rides down steeper hills on moist or slightly tall grass.
I have a standing order with Barlows to call if he gets a F low hours trade in so I can try and negotiate a deal to trade my 50 hour ZD1211 to another F.
I to sometimes reach behind me and wipe off screen when real dusty/dry and fine grass may somewhat cover screen behind the seat. Checked air filter on ZD and it was covered in dust but never had to clean the air filter on the Fs. The ZD has a port that sucks in the air/dust straight to air filter.

 

[RickB]

The F3990 and B3350 share a very similar emissions system which has proven to be problematic and unreliable. Comparing the reformer type system to that used on larger L series Kubotas is an apples to rutabagas comparison.