Hi. First post here. I have a zd28 it starts right up fine and will run good for a few minutes or sometimes a hour or so before it acts up. When i have the blades engaged, ill be mowing along and I have a loss of power almost to the stalling point then it will slowly come back. It will then run good for a few minutes and the power drops again. It surges and sputters but it's getting worse. I have changed the fuel filters, checked oil level/coolant, air filter is clean and rad screen is clear. It never runs hot. I notice it happens a lot as I'm making a turn around, but also doing it in a straight line. Any help would be greatly appreciated. Thx
zd28 running rough
- Thread starter xro
- Start date
I'm guessing that it is a gas motor? If it is, the first thing I would check is the Magneto. It is probably heating up and the spark is breaking down. And after you shut it off it will cool off and run normally until it heats up again. If this is what it is, it will be a simple replacement. Good Luck
Crud in the fuel tank blocking the outlet? The turning part seems interesting.
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When you changed the fuel filter did it have much trash or water in the fuel?
Did it have any fine black looking specs in or around the filter?
Do you use it commercial or residential?
Do you filter your fuel when you fill it up?
Have you ever used any diesel conditioner in the tank?
From the info you have given it makes me think of algea, water or some other kind of trash in the tank.
Did it have any fine black looking specs in or around the filter?
Do you use it commercial or residential?
Do you filter your fuel when you fill it up?
Have you ever used any diesel conditioner in the tank?
From the info you have given it makes me think of algea, water or some other kind of trash in the tank.
I've been having the same problem with my ZD28. It started with a little less than 300 hours on the engine and still having the same problem. I've brought it back to where I purchased it from 3 or 4 times to let the mechanics try and fix it. The 2nd time the head mechanic said it sounds like the clutch is bad. Me not being a diesel mechanic told him to do what he had to do to fix the problem. The Kubota Rep from Dallas, TX came in to look at it and said change the clutch out even though it didn't have that many hours on it. Kubota paid for the parts but I had to pay $950 labor. I bought it home and ran it for 30 minutes, got pissed off and loaded it back up to bring back to the shop because it wasn't fixed. After several more trips back and forth they just told me that they couldn't figure out what the problem was and they couldn't fix it !!! I asked if they checked to see if the injectors were bad and they told me they didn't have a "pop tester" to see if they were bad or not. So I had to take the injectors to another diesel mechanic to get them tested and they were fine. I have over 400 hours on it now and can't even cut grass for more than 30 minutes without it losing power. I've taken the tank off several times to clean it, changed more fuel filters out than I should have, tested the fuel pump to see if it was pumping enough fuel, changed the fuel lines out several times plus ran them a different way just in case they were collapsing, had the fuel injector pump checked out and it's still starving for fuel after it warms up (30 minutes or so). Pretty crappy that a certified technician/ mechanic told me he didn't know what the problem was and couldn't fix my mower after charging me $950 for labor for changing a clutch out that didn't need to be changed in the first place, his words not mine !!! Plus the $12,000 plus I paid for the mower brand new. I only use it for personal use and not commercial use. I would appreciate any input from anybody that knows anything about this problem that I'm having. Really close to bringing it back to the Kubota dealership and telling them to keep it because it's no good to me if I can't even cut my grass with it !!!!!!!!
ZD28 - An easy one to try, sometimes easy ones fix probs, sometimes they don't. Remove the fuel cap and get a rubber band and a rag to cover the hole, this allows air into the tank. Run it like this and see if it still does it.
So there is a fuel problem, possibly vacuum in tank, reason for running without cap, or possibly filter problem, have you replaced the filter under the mower at the fuel tank outlet as well as the one on top of the engine?
Also check your PM's, have sent a link for a WSM
The filters that you changed out they didn't have a slime looking substance in them did they. Sounds like the same thing my bx2200 was having. Turns out I had an algae in my fuel. Treated the tank and changed the filter problem went away runs fine now.
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I'm betting a blockage in the tank. It is acting like a fuel starvation issue. If filter is good and lines are good then check the tank.
I had a similar problem with a diesel mower. Some times it would work for days them others it would die several times. Finally realized that someone had dumped pea gravel in the fuel tank and it would roll around the bottom till the fuel line sucked a bunch to the end and starve the engine for fuel. As soon as the engine was shut off the gravel would fall off the end and normal flow would resume. Very difficult to trouble shoot.
I had a similar problem with a diesel mower. Some times it would work for days them others it would die several times. Finally realized that someone had dumped pea gravel in the fuel tank and it would roll around the bottom till the fuel line sucked a bunch to the end and starve the engine for fuel. As soon as the engine was shut off the gravel would fall off the end and normal flow would resume. Very difficult to trouble shoot.
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Thanks for the help guys and the link ! I've changed the lines, changed the filters, cleaned the tank and ran the mower without the fuel cap. Still after about 30 minutes it still bogs down. I would love to bring it back to the shop again but I don't think I can handle the mechanic telling me again he can't figure it out either. I just might lose it !!!! I've emailed Kubota Corporation and they won't even call or email me back !!! Done that several times in the past year. I call that pitiful customer service !!!!! Don't know what to do.
Daren Todd
Well-known member
Lifetime Member
Equipment
Massey Ferguson 1825E, Kubota Z121S, Box blade, Rotary Cutter
I'm thinking a possible wiring issue in one of wires going to your safety switches. Possibly near a heat source causing the connection to get hinky as it heats up causing expansion. Or loose connection in one of the quick connectors in the wiring harness.
coachgeo
Well-known member
Equipment
L225 w/woods Few Mowers & Back Blade, D722 in Motorcycle (Triumph Tiger), LMTV
Im thinking heat causing conflict with something is a possibility too.
If you fart around with the fuel system any more try taking the tank out of the picture. use a make shift tank say a boat tank borrowed from neighbor or even a Gal. jug orrr? and by pass everything you can between tank and IP. Use a different inline fuel filter too.
See what happens then. Reason I bring this up.... Did a quick search and there was a fair amount of discussion on this model getting a plugged fuel line from tank to first inline filter. Enough so that fuel flowed and air compressor would blow thru line fine... but not until they actually cleaned the line with a cloths hanger did things change successfully. Several reported this.... but you've said you replaced fuel lines though?
Other rambling ideas
Go to Harbor Freight and get a diesel compression checker. Check it when it is cold..... and when it is hot (after it bogs down).
Head Gasket? When it is hot expansion allows for compression loss?
Valve seat? When hot and things expand compression loss at a valve?
Is there a decompression pull on the engine? could about a half hour of vibration on something loose be causing it to move some? Maybe disconnect the cable for shiatz and grinz and see if something changes?
ahhh..... run it for a half hour NOT MOWING. Heck try the same with it just sitting there. Could it be something is wrong in the hydraulics and the bog down is actually caused by the engine not being able to move a hydraulic pump cause it is freezing up/binding.
hmm.. do you have an oil pressure guage?
If you fart around with the fuel system any more try taking the tank out of the picture. use a make shift tank say a boat tank borrowed from neighbor or even a Gal. jug orrr? and by pass everything you can between tank and IP. Use a different inline fuel filter too.
See what happens then. Reason I bring this up.... Did a quick search and there was a fair amount of discussion on this model getting a plugged fuel line from tank to first inline filter. Enough so that fuel flowed and air compressor would blow thru line fine... but not until they actually cleaned the line with a cloths hanger did things change successfully. Several reported this.... but you've said you replaced fuel lines though?
Other rambling ideas
Go to Harbor Freight and get a diesel compression checker. Check it when it is cold..... and when it is hot (after it bogs down).
Head Gasket? When it is hot expansion allows for compression loss?
Valve seat? When hot and things expand compression loss at a valve?
Is there a decompression pull on the engine? could about a half hour of vibration on something loose be causing it to move some? Maybe disconnect the cable for shiatz and grinz and see if something changes?
ahhh..... run it for a half hour NOT MOWING. Heck try the same with it just sitting there. Could it be something is wrong in the hydraulics and the bog down is actually caused by the engine not being able to move a hydraulic pump cause it is freezing up/binding.
hmm.. do you have an oil pressure guage?
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Im also leaning towards a wiring fault, as wiring heats up,a power drain from fuel solenoid to another circuit or ground. Tapping circuit and backing off fuel solenoid. Unplug and re-route any wiring near heat sources. Also check tour positive and ground battery cables on both ends. Best to remove and clean.
Had a watercraft that recently went bonkers due to a loose battery cable. I know its not a diesel tractor, but wierd electrical issue is the common factor here.
Had a watercraft that recently went bonkers due to a loose battery cable. I know its not a diesel tractor, but wierd electrical issue is the common factor here.
coachgeo
Well-known member
Equipment
L225 w/woods Few Mowers & Back Blade, D722 in Motorcycle (Triumph Tiger), LMTV
I'm sure you've read it but here is a thread on the same topic ... their was blockage not in a line..... but in a "T"
http://www.orangetractortalks.com/forums/showthread.php?t=4672
http://www.orangetractortalks.com/forums/showthread.php?t=4672
Thanks for all the help guys. I'll try everything y'all have shared. It might take a while but I will let y'all know what happens good or bad.
