Kama 554 arrived this AM!

[greg_g]

Re: I got in some seat time.

I especially like bush hogging with the 1000RPM gear and running the engine at about 1100RPM. I ran mostly in 2 high.

I hate to throw a negative into an otherwise positive thread, but you're gonna eventually break something that way. It's just fortunate so far that you describe your bush hogging as light duty. Sounds like you must be on pretty flat ground too.

I don't know of a single rotary cutter transmission that's designed to spin at 1000 rpm. There's an equation that the design engineers use to get effective blade tip speed from specific gear ratios at specific rpm speeds. You'll find the vast majority of implements you purchase for that tractor should be operated at 540 rpm. Also, there's a green mark on your tachometer. Set your throttle so the tach needle is in the green, that's your PTO operating zone. Seldom any lugging of the engine or dropping of the blade tip speed that way. Makes for more consistent mowing, and easier all around on equipment. Makes little difference on fuel consumption.

I think we have the same transmission. I do most of my 540 rpm mowing in L3 at about 2200 on the tach, some smooth flat stretches in L4. If you have the same tranny, you'll find that H1 is slower than L4. I find H1 handy in some mowing conditions where L3 is too slow but L4 is too fast.

//greg//

 

[schmalts]

Gregg, i think what he is saying is that he puts the PTO in 1000 RPM and runs the engine at half the speed of normal since is has so much power. I do the same with my finish mower. I put it in 720 PTO speed and put around the field at little over 1400 rpm. The PTO will not overspeed the brush hog as long as he never revs the engine past half of what the RPM range is for the 500PTO marking on his tach. Why run the engine RPMs up if you can let the beast purr at a nice low speed. Really helps out keeping it running cool on hot days as well.

 

[3RRL]

My PTO speed is also 540/720 rpm. Man, I wish I had the 1000 PTO rpm. When running implements as the brush hog, PHD and PTO driven backhoe pump, I do the same thing. I run the engine rpms no more than 1725rpm in the 720 PTO range instead of rated 2300rpm in the 540 PTO range. (Usually around 1500 to 1700) That rpm range coincides with where maximum torque is made by the 495T2 engine (around 1600 rpm). It cruises along nicely and is also a miser on fuel. I figure torque is what gets me there and horsepower keeps me going. The engine is so powerful that I don't need to run it at any higher rpms for "run of the mill" stuff.

I run the brush hog in 540 PTO range at 2300rpm when I know I'm going to cut some 3' saplings so as never to bog the Kama down. because that's the rpm where peak horsepower is made. I don't use the 540 PTO with the PHD though. I would rather have the engine start to bog and alert me when using that implement. Save's me twisting or busting something off or getting the auger stuck...
All in all, I'm tickled pink with my Kama 554.

 

[Brad_Blazer]

You know, I am not positive whether I have the 1000 or 720 RPM option. Is there a way to check other than timing the shaft? I'll call the dealer tomorrow and try to confirm. The guy who delivered it did say 1000 rpm but I don't see it written anywhere. The bush hog cut fine but I had just sharpened the blades.

At any rate, I feel much better about running at reduced throttle when full horsepower is not needed. In the hypothetical hard scalp or similar situation I would rather not have full rated horsepower available to the implement. Another plus is better speed selections since at half throttle the speed difference between gears is also cut in half.

Of course we do need to take care not to overspeed anything.

Greg that's a good point about 4L being half way between 1H and 2H.

Brad

 

[greg_g]

The guy who delivered it did say 1000 rpm but I don't see it written anywhere.

The guy told you wrong, the mower is engineered to operate at 540. Speed select lever on KAMA554; middle detente is neutral, down is 540, up is 720.

Greg that's a good point about 4L being half way between 1H and 2H.

I'm not sure how you extrapolated that conclusion Brad. There are four gears (1-2-3-4) that you can operate in two ranges (H-L). H1 is geared for ground speeds that are faster than L3 but slower than L4. Gear/range select in order of ground speed - slowest to fastest - L1/L2/L3/H1/L4/H2/H3/H4.

...when full horsepower is not needed

Torque does the work on these tractors Brad, not horsepower. Note that your owner's manual states that working torque is not developed by your engine until 1750 rpms (1680 if you have the -T2 variant). Anything lower than that and you're actually lugging the engine. May not sound like it, but they're designed to work in the rpm range between max torque and full throttle. It's no coincidence that the green mark on the tach (PTO rpms) is in this range.

//greg//

 

[Brad_Blazer]

The guy told you wrong, the mower is engineered to operate at 540. Speed select lever on KAMA554; middle detente is neutral, down is 540, up is 720. //greg//

I just confirmed it with my dealer. Mine has the 1000rpm upper range on the PTO. In my manual it shows 3 options: 540-720, 540-1000, and 720-1000(yikes).

I'm not sure how you extrapolated that conclusion Brad. There are four gears (1-2-3-4) that you can operate in two ranges (H-L). H1 is geared for ground speeds that are faster than L3 but slower than L4. Gear/range select in order of ground speed - slowest to fastest - L1/L2/L3/H1/L4/H2/H3/H4. //greg//

I guess I confused you by writing 1H instead of H1. I was just pointing out the portion of your sequence that goes H1/L4/H2. I think it was more of an interpolation.

Torque does the work on these tractors Brad, not horsepower.
//greg//

Is that special chinese physics? Where I went to school, the opposite of that statement is true. Work is the product of power and time. Torque alone applied for a period of time = stubborn, like what your brakes are doing when parked on a hill. In terms of power actually produced by a tractor engine, setting the throttle at a certain point only establishes the limit of available power. The load you are working against is what dictates the power delivered by the engine. That's the difference between putting an engine on a dynamometer and revving it in neutral. The published power output is almost universally based on a wide open throttle setting. Torque vs. RPM is the same data set as power vs. RPM i.e. given one you can easily calculate the other.

If you can't tell when your engine is lugging, maybe you need to be more diligent with the hearing protection running everywhere at full PTO rpm. (I'm sorry, I couldn't resist)

Let me explain what I was doing: I was cutting drought stunted grass and weeds mostly on the flat using a 5' bush hog. My engine was running at about 1100RPM so the PTO was turning at about 500RPM. When I got to a hill or sharp turn, I downshifted from 2H to either 1H or 2L. I was diligent in downshifting since I am breaking it in. If I had to make a SWAG, I would say I was using about 15 HP. If I followed your advice I would have about 50 PTOhp on tap to the hog. Counting momentum of the full speed engine, If I something bad happened to the implement I'm sure the momentary power would be a couple of times that. The phrase "you're going to break something" comes to mind. Of course, its academic - a bush hog is designed to take quite a bit of abuse.
My best story of worst case implement failure was the dairy farmer I worked for in HS chopping hay for silage. 85hp tractor at full PTO speed pulling a Fox chopper and a mostly full chopper box. For some mysterious reason one of the helical chopper blades decided to come down ON the cutter bar instead of past it. Nothing sheared off. The tractor snubbed instantly and skidded about 10 feet. The only thing damaged was the chopper blade support that was bent out and had a small crack on the side under tension. (of course the blade itself was somewhat damaged also).

Anyhow Greg, please feel free to enlighten me if American physics does not apply to Chinese tractors.

Bradley J. Blazer, PE
BSME NCSU
(very) formerly a farmhand in America's Dairyland.

 

[greg_g]

Anyhow Greg, please feel free to enlighten me if American physics does not apply to Chinese tractors.

I get the feeling it would be a waste of time. You've quite obviously got a single mindset on how you want to use your tractor, and it's not my place to tell you otherwise. Best of luck with your new purchase.

//greg//

 

[Brad_Blazer]

Greg,
Thanks for posting. While I may not agree with all of your viewpoints, they are certainly thought provoking. I have read your posts on several forums and your positive experience with your Kama was a contributing factor in my decision to purchase. Thanks for sharing.

Best regards,
Brad

 

[Captinjack]

Brad
I have a Kama 554 but have a pleated air filter, seat belt, remotes, no PTO guard. The decompression acturator is not connected, but starting is great except in 10 deg. and below. Intake has some kind of preheater but it is not connected nor mentioned in the manuals or parts book.

I have 75 hrs. on mine and am more impressed as time goes on. I have a weeks vacation over the fourth of July and will be doing more grading work if I can get the flat rear tire fixed.

Good luck and keep in touch.

ps Yes. Mine whines noticeably in reverse. The lever for 4 WD slips out too. I wish I had the tools and skills that 3RRL has. I'm using the cave man bungee cord to keep the lever back in 4 WD.

 

[Paddy]

I have a KAMA 454 I got from Chip of Artrac. I have been impressed with the tractor and dealer from day one. A bit noisy in reverse too. And yes slips out of 4x4 so I too use a bungee cord.

I'm at 50 hrs now so I will be doing a fluid change soon.

I reccomend you hook up your De-compression and pre heat. Save those starters!

Patrick