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ddckk
05-19-2005, 06:36 PM
I bought a a ZG 20 and I have had it at the dealer 3 times , they keep doing different things to get it to cut better byt after 3 different times it still misses grass , 1 they put a baffle on it , 2 they sped the motor rpms from 3300 or so to about 3500 or so , 3 they took the engine rpms to 3800 it still misses grass , anyone know if there is anything they are missing , and they checked the deck levelness also , thank you .

grass disaster
05-19-2005, 06:44 PM
I bought a a ZG 20 and I have had it at the dealer 3 times , they keep doing different things to get it to cut better byt after 3 different times it still misses grass , 1 they put a baffle on it , 2 they sped the motor rpms from 3300 or so to about 3500 or so , 3 they took the engine rpms to 3800 it still misses grass , anyone know if there is anything they are missing , and they checked the deck levelness also , thank you .


try to sharpen the blades?

Envy Lawn Service
05-19-2005, 06:52 PM
I am usually able to help out with this when your dealer can't.

Tell me about the missing....

What is it missing? (Weeds/Grass/stems/wide blades/whispy blades)
Where in the cut is it missing?
When is it missing?
What seems to make it better and worse?

I'll be back to help later tonight.
But rest assured there IS something wrong with your mower.
Don't let them bluff you into believing otherwise.
That deck cuts extremely clean when right....

ddckk
05-19-2005, 07:00 PM
They also sharpened the blades , it only has 13.5 hours on it , it misiss different things , and it does it in different places in the deck , at first I thought it was the tip speed butt they told me it should be around 17500 or 18000 , does anyone know how to check the blade speed , thank you.

ddckk
05-19-2005, 07:14 PM
It leaves twigs and patches , in any kind of grass , it is worse the taller the grass is and if you go slow like walking speed it does great but thats not why I bought a commercial ztr , my 36 inch walkbehind has a blade speed of 17500 and it does good even in taller grass , it leaves more in yards with weeds , my yard is fescue and it leaves some but not as much , I would say it leaves about a twig or patch of grass every 10 to 20 feet , thank you.

grass disaster
05-19-2005, 07:16 PM
They also sharpened the blades , it only has 13.5 hours on it , it misiss different things , and it does it in different places in the deck , at first I thought it was the tip speed butt they told me it should be around 17500 or 18000 , does anyone know how to check the blade speed , thank you.

how about you answer envy's questions!!!! you might get your answer. quit dancing around. it sounds like this guy knows what he's talking about.

chuckers
05-19-2005, 07:27 PM
did you try different blades that mite make the difference

grass disaster
05-19-2005, 07:37 PM
how about you answer envy's questions!!!! you might get your answer. quit dancing around. it sounds like this guy knows what he's talking about.

never mind your too quick for me

ddckk
05-19-2005, 08:06 PM
I thought about the blades but have not yet tried them , the dealer tells me it has about the highest lift blades there is , thank you .

specialtylc
05-19-2005, 08:44 PM
The ZG20 is a heavy duty residential mower, not a commercial unit. But it should still cut good. I think the blade speed on the ZGs is about 14,000 fpm. The speed up gear kit for the ZDs may work if they use the same gear box on the deck. It will really make a difference it it has the lower blade speed.

Envy Lawn Service
05-19-2005, 11:48 PM
Well, the ZG passes for commercial in my book. It has a drive system superior to the ZD... and aside from a lack of stripe, the deck out performs anything else I've seen on the market.

Look, I had a ZG 23 with a 54" deck here for a while. I used it to take some rough-cut areas down to a clean finish. I was able to do so at speed and achieve a perfectly clean cut. What's more is I was able to do so and leave it after a single pass. Nothing left to cut down and no excess clippings needing re-chopped.

Nope, don't know of another commercial mower that could have done that. Something is wrong with this guy's mower. No question about it. The blade tip speed is 15,800 fpm at the low factory rpm setting. In contrast the ZG 23's blade tip speed is 16,000 fpm. No, these are not the blistering 18,000-19,000 fpm of other mfg's. I don't think that matters though, and I'm sure it's close now at 3800 rpm engine speed.

Let me hunt a link to help out....

Envy Lawn Service
05-20-2005, 01:41 PM
In for lunch.... OK... first check all your belt tension and tension pulley to make sure it is not over-center. Also check to make sure your blade bolts are tightened to spec. We wanna make sure nothing is slipping under pressure.

Next here is a quote from where I was helping someone else....

But before starting this process, be sure to force the blades to slip around so you can see how they match up with each other where they meet. Sometimes this will reveal something. If not proceed....

Since your deck is stamped though.... you will have to get the mower to a nice flat polished conrete area or somewhere REALLY FLAT. Then you will have to measure from the surface up to the blade tip instead of from tip to deck top. Understand?


You will need:
1- note pad
1- pen
1- scraper/putty knife
1- folding wood ruler (I use a mason's ruler)
3- standard OEM blades (checked for straightness and mating of course)
#- lots of patients

Lift mower
Remove blades
Scrape deck top totally clean
Install blades from above
Lower mower
Set all 4 tires to proper PSI per manual (not tire side)
Lift mower to transport or a high cutting postion

Starting with left blade position blade straight front to back like so ( l \ / )
Measure from bottom of front tip to deck top and record measurement on pad
Measure from botton of rear tip to deck to and record measurement on pad

Position center blade straight front to back like so ( \ l / )
Measure from bottom of front tip to deck top and record measurement on pad
Measure from botton of rear tip to deck to and record measurement on pad

Position right blade straight front to back like so ( / / l )
Measure from bottom of front tip to deck top and record measurement on pad
Measure from botton of rear tip to deck to and record measurement on pad

Now copy 3 front and 3 rear measurements down in a left to right row:

Example
Front : LF ____ CF ____ RF ____
Rear : LR ____ CR ____ RR ____

Examine/compare measurements.
Do you have a suspect?


In any event, if you see something there, you have a SUSPECT.
Instructions for further investigation of SUSPECT are forthcoming.

shortgut
05-20-2005, 02:40 PM
this is the main reason that I sold my Kubota ZD 28 -60 pro it would leave grass standing even with a speed increaser kit so I went back to what I knew would work for me another Scag mower . If kubota can get there deck to cut like the Scag then they will have a really top of the line machine, but I got tired of having to double cut I even tried other blades and at timees it would leave shooters standing when the Scag would be cutting it fine .

Jay's Lawncare
05-20-2005, 03:29 PM
interesting, ive heard a lot about the kubota mowers i.e. zd's/zg's and from what im hearing, it doesnt seem to be worth the price they are wanting for them. My two mower choices were the zd 28 and the lazer zxp, thanks guys for helping make my decision easier.

ddckk
05-20-2005, 05:40 PM
I measured the blades mand the LF 5 inch LR 5 inch ,CF 4 11/16 CR 4 11/16 ,RF 4 11/16 RR 4 14/16 , that was in my garage the most level place I could think of , the left side seems a little of but not sure if that is the way their suppose to be , thank you.

chief5139
05-20-2005, 05:46 PM
kubota is a great machine no one else has anything on the market that can touch it. all drive shaft drivin' wet clutch pto engadgment, 7ga deck and on the zd models if you will look the kubota deck is identical to the exmarks to .

chief5139
05-20-2005, 05:52 PM
oh yea for got the on board jack on zg models and pivioting axel jack in the zd models

prolawncorp
05-20-2005, 06:00 PM
Let me suggest thsi as I talked to a friend of mine who worked for Snapper in the commercial area. When a mower leaves strips at high speed and not at low speeds is the air flow of the deck or blades. THis means then blades are not lifting the grass up to cut. So he said the first thing to do is

a) Pitch the deck forward about 1/4" to 1/2" nose low- This will cut the air from blowing out the front of the mower.

b) 13,500 FPS is ok if your moving at 4 mph but to go faster you hvae to be at 16,000 which is hard to test but if they increased the engien speed your close.

Hope this works let me know

ddckk
05-20-2005, 09:11 PM
I cant even mow 4 mph , the only way it cuts real good is around walking speed , as for the tilting of the deck I will look into that thank you .

Envy Lawn Service
05-20-2005, 09:36 PM
I measured the blades mand the LF 5 inch LR 5 inch ,CF 4 11/16 CR 4 11/16 ,RF 4 11/16 RR 4 14/16 , that was in my garage the most level place I could think of , the left side seems a little of but not sure if that is the way their suppose to be , thank you.

SORRY!

Sounds like something is rotten in Denmark.... but you're gonna have to move the mower a couple of places to confirm these measurements. Don't go off in left field giving the deck more pitch just yet either. Actually you will want to make further attempt to get things as dead level as possible so you can see just where you stand.

Sounds like you are level front to back at the left and center blade.
Sounds like the deck is lower on the right side.
3/16 and 5/16 is a lot!!!

What I think you will find.... assuming your current measurements are confirmed.... is that you will be able to bring the center blade up to 5" to match the left. But the discharge blade is gonna be off. In other words, when you lift the right side of the deck far enough to bring the center blade to 5" which will have both the left and center blade totally level at 5".... the discharge blade is going to have 3/16" forward pitch.

Probably something that happened during the MFG process. I had a deck with a similar problem, except mine had a 3/16" reverse pitch on the center blade. Cut problems you would not believe. It's not so much of the deck being off that bad... but more of the fact one blade is not spinning and creating air flow on the same plane.... so the blades create turbulence and interfere with each other's ability to cut.

It would actually be VERY helpful to you if say your deck uses blades with a 5/8" center hole to go down and pick up a set of exmark notched foil blades just to check this deck out better. These blades are flat/straight and you can lay a 4' level right on them to see where you stand rather quickly.

I was able to do that with mine on top of the blades, on bottom of the blades, and across the spindle bases like so...

zgman
05-21-2005, 03:10 AM
with 13 hours on it, you shouldn't have to do anything. Kubota needs to address the issue. If the dealer can't figure it out, they need to get you a new unit. My ZG20 leaves a great finish.

pcnservices
05-21-2005, 08:16 AM
Great help here Envy! The measurements he gave seems like it is within tolerance but the deck is not pitched. I think he should try and pitch the deck forward (nose down) ± 1/4 inch and see what it does.
I would also suggest doing the same measurements from the outer rim (or skirt) of the deck to the floor.