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Also, the 25 hp Kubota Diesel that will be on the new exmarks should be more than enough to power those machines from my experience. A large horse farm that we mow has an older Kubota outfront 4wd with the same engine and a 60 in deck. It will go through really thick wet grass with very little to no bog, and that's also pushing 4wd and a shaft gearbox. It cut's like crap, but that's due to the old stamped deck design, not the engine. With the newer deck designs, the engine should have it easier I would think. I think Exmark is making a wise decision going to Kubota engines. The horse farms around KY use mostly Kubota mowers from what I can tell, with a lot of them being run all day and every day.
 
Cut a 72" swath of 8" of thick growth down to 4", going uphill, at 8-10 mph, at ~19,000'/m blade speed with hight lift blades. The 42 lb/ft of torque Kubota will choke.
 
TLS said:
Cut a 72" swath of 8" of thick growth down to 4", going uphill, at 8-10 mph, at ~19,000'/m blade speed with hight lift blades. The 42 lb/ft of torque Kubota will choke.
A Friend that has a 2001 26Hp FI said, when he tried the 31 60" going up a hill that he has with his mower it would bog a little, i said what did the XS do? He said he pushed on the levers and it popped a wheelie :p

Tommy try one please ;) You will never talk Liquid again :waving:

John
 
John,

I DID demo both a 60" and 72" XS.

I was VERY happy with the performance (could always use more speed), but didn't like the fact that it's a 1500lb A/C ZTR. Plus, though the power of the Briggs impressed me, the sound did not. And, from what I hear, they are thirsty!
 
TLS said:
John,

I DID demo both a 60" and 72" XS.

I was VERY happy with the performance (could always use more speed), but didn't like the fact that it's a 1500lb A/C ZTR. Plus, though the power of the Briggs impressed me, the sound did not. And, from what I hear, they are thirsty!
Cost offset???? Isn't that what the diesel heads say???????????
 
I saw that link the other day as well.

23hp??? :help:

They're claiming it's able to power through conditions that would strain a gas engine.

So I'm gonna take a guess as this is what they will use in the eXmark's as well.

Definately NOT going down to a 23hp.

Seems this is the effect of the engineering teams feeling the fuel price hike of Katrina, and downsizing engines to squeak better economy out of them.

Definately NOT the same engineers that worked on the XS.
 
I run two Kubota diesels. Can't beat them as far as engine performance.
I don't like Kubota's deck design, doesn't cut as good as some mowers.
I am looking at Hustler's 34 hp Cat . 70ft torque at 1800rpm. Engine will last
forever. But it's $16000. That price I will be the only operator.
 
TLS said:
I saw that link the other day as well.

23hp??? :help:

They're claiming it's able to power through conditions that would strain a gas engine.

So I'm gonna take a guess as this is what they will use in the eXmark's as well.

Definately NOT going down to a 23hp.

Seems this is the effect of the engineering teams feeling the fuel price hike of Katrina, and downsizing engines to squeak better economy out of them.

Definately NOT the same engineers that worked on the XS.
One final word on horsepower. Name plate ratings on Gas engines are normally what is called gross horsepower. That is what the engine will produce without a muffler, without an air-cleaner and without any accessories such as an alternator. Diesel engines tend to be labeled by their net horsepower, that is what they actually put out the PTO. This can make a huge difference. Let's compare the new Kohler 30 horsepower gas engine versus this Kubota D902 23 hp diesel engine. Displacement: Kubota, 898cc; Kohler, ~735cc. Maximum shaft output torque (Net): Kubota, 45 ft-lbs; Kohler, 38 ft-lbs. Which engine do you think actually puts out more shaft power and will have the best performance in the grass? Me thinks the Kubota.
 
Where are you getting your Kohler specs from?......

Specs for the CH750 and CV750 models:
Power @ 3600 rpm
Maximum 30hp / 22.4 kW
Recommended 25.5hp / 19.0 kW
Displacement 45 cu. in / 747 cc
Bore 3.3 in. / 83 mm
Stroke 2.7 in. / 69 mm
Peak Torque CV750: 47.1 lbs.ft. (63.8 Nm) at 2600 RPM
CH750: 47.5 lbs.ft. (64.4 Nm) at 2400 RPM
Compression Ratio 9:4:1
Dry Weight 105 lbs. / 47 kg
Oil Capacity w/filter 2 US quarts / 1.9 liters
Dimensions (L x W x H) CH750 W/ heavy-duty air cleaner: 14.0” x 17.7” x 27.8”
CV750 W/ heavy-duty air cleaner: 20.5” x 17.7” x 22.5”
 
TLS said:
Where are you getting your Kohler specs from?......

Specs for the CH750 and CV750 models:
Power @ 3600 rpm
Maximum 30hp / 22.4 kW
Recommended 25.5hp / 19.0 kW
Displacement 45 cu. in / 747 cc
Bore 3.3 in. / 83 mm
Stroke 2.7 in. / 69 mm
Peak Torque CV750: 47.1 lbs.ft. (63.8 Nm) at 2600 RPM
CH750: 47.5 lbs.ft. (64.4 Nm) at 2400 RPM
Compression Ratio 9:4:1
Dry Weight 105 lbs. / 47 kg
Oil Capacity w/filter 2 US quarts / 1.9 liters
Dimensions (L x W x H) CH750 W/ heavy-duty air cleaner: 14.0” x 17.7” x 27.8”
CV750 W/ heavy-duty air cleaner: 20.5” x 17.7” x 22.5”
Couldn't remember the exact displacement. But the outputs in their specs for torque and horsepower as you are showing are GROSS outputs, not actual in the machine NET outputs. They are also showing wide open throttle data versus governed. My data is for machine configured engines with air-cleaner and muffler with governed output from actual engine dyno testing by an independent lab. This is how engines should be compared--as actually used. The differences are not unusual, they are typical of gas engines.
 
I just discovered that they DON'T put this engine on the 72"ers. While it may be adequate for their 52" machine, the 60" will still be marginal at best.

Almost confusing....take a look at this chart supplied by TORO.....Interestingly enough it's comparing a 30hp gas to this 23hp Kubota.

 
TLS said:
I just discovered that they DON'T put this engine on the 72"ers. While it may be adequate for their 52" machine, the 60" will still be marginal at best.

Almost confusing....take a look at this chart supplied by TORO.....Interestingly enough it's comparing a 30hp gas to this 23hp Kubota.

we need mowtech to explain the graph and tell us why the diesel is best, cuz i still don't quite understand.
 
Yes, I've seen this, that's why I tried to make the same comparison. Horsepower is tricky as in the past engine manufacturers have used different rating methods for labeling their engine horsepowers. So you are not always comparing apples to apples which obviously can be misleading and confusing. There is actually a class action law suit currently going on against small gas engine manufactures related to this horsepower labeling. Because of this, in the future we will see more consistent ratings across all manufactures which will make everyone's life easier when making engine selections. But in the meantime, consider that relative to horsepower ratings, diesels are generally rated on NET outputs while gas engines are rated on GROSS outputs which in general overstates what they really provide to cut the grass.
 
Explain this.....

Kubota
 
Okay, the Kubota curves are wide open throttle curves. This is what the engine produces when used in a variable speed application such as a truck. Left side of the graph is the engine throttle pulled back to low idle while the right side shows the throttle opened all the way to maximum speed. The Kubota curves, for that matter those of most Japanese diesel manufacturers are quite accurate except that Japanese diesel fuel has slightly lower energy content than US fuels so they are slightly under what the engine will produce in the USA. Kubota is providing both NET and GROSS ratings on the graph. The INT means intermittent--they don't want you running the engine at full output all the time. The Toro curves shown are governed curves, particularly governed torque curves. This is how an engine is used in a mower. The graph shows the engine performance at the high idle setting where you generally run it while mowing. Right side of the graph shows the output under no load--at no load the output torque is zero and engine is running at its top speed. Torque is produced as load is applied. As you move to the left on the graph the output torque corresponds to the load--the further left you move on the graph the greater the load on the engine and the more it droops under load. What Toro is showing is that the Kubota puts out more torque than the 30 hp gas engine without saying that the Kubota produces more hp because then you would be getting into the horsepower rating question which is confusing (I think!)

I admit I have a bias to diesels because I've worked with them a lot over the years, but I am not trying to sell anyone on diesels. I've posted enough on the advantages and disadvantages. Only you can decide what is right for your operation. Only you can decide if the diesel is worth the added out of pocket cost. Only you can decide how much hp you need. My point only is to be careful when comparing hp, especially between diesel and gas engines. When it comes to price and things like fuel consumption and weight, if you compare a 30 hp gas engine to a 30 hp diesel to make your decision, you will not be comparing the right engines.
 
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