# Engine RPM



## guest2 (Dec 27, 2003)

OK, I know this might be a stupid question but it's something I need to know once and for all. When you guys (gals?) use your tractors are you running at WOT or part throttle? I've always run all machines at WOT unless idling down to shut them off, or for a few minutes to warm them up. I've seen many posts around at other forums of people not running at full throttle. They seem to think that it'll blow up or waste gas maybe. I believe it to be worse for the engine to have any kind of load applied at less than WOT. Am I wrong? Doesn't it cool better, have less carbon build up, and less stress at full speed? What would the reason be to run it at 2/3 throttle? That has to be more stressful on the crank, rod, and piston right? Running at 2/3 throttle really isn't "babying" an engine is it? And since every manual I have for every piece of equipment from tractors to lawn mowers, log splitters, pressure washers,etc all state to run at full throttle, where do some get the idea that it's better to ignore the manufacturer and do differently? Enquirering minds need to know!


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## Ingersoll444 (Sep 17, 2003)

Well if I am realy using it,ie mowing, plowing, tilling,etc, I always run full. Now just moving from one part of the yard to anouther, or towing a light cart, I am normaly at 1/2-3/4. Yes there is less load on the lowerend of the motor, at speed, as long as the motor is not so low you are lugging it, it is nothing realy to worry about.


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## MowHoward2210 (Nov 2, 2003)

WOT seems to be the recommendation for the more modern L&G tractors, mainly for cooling reasons.


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## guest (Sep 16, 2003)

cutting & snowblowing... wide open.. driving around or pulling something.. not always WOT


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## jodyand (Sep 16, 2003)

It is best to run at full speed that might not be what some will say but it is design to run wot for cooling. Ya ll up north might not make that much deferents but down south here when it gets hot you can burn one up running it slow. Because you are not moving the air you need to move to cool it. I run mine at idle for about two min to warm up and at shut down thats it wot the rest of the time.
Jody


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## KevinJD325 (Sep 21, 2003)

cutting & snowblowing... wide open.. driving around or pulling something.. not always WOT

Same goes here!


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## Ingersoll444 (Sep 17, 2003)

> _Originally posted by jodyand _
> *It is best to run at full speed that might not be what some will say but it is design to run wot for cooling. Ya ll up north might not make that much deferents but down south here when it gets hot you can burn one up running it slow. Because you are not moving the air you need to move to cool it. I run mine at idle for about two min to warm up and at shut down thats it wot the rest of the time.
> Jody *


Good points about the cooling JA, BUT,[and there is always a but ] One thing to remember, when you do not have a real load on the motor, it is not putting out as much heat. In that case it does not need as much airflow. I think we would be better off making sure all the fins are clear under the tin, than to worry about that little bit of extra air top speed provides.


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## guest2 (Dec 27, 2003)

So, is it more dependant on the type/size of engine?


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## Argee (Sep 17, 2003)

I think this is something where one would use their senses to answer that question. Does it feel to hot? Does it smell hot? If you answered yes to either one of these then you need more throttle.


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## guest2 (Dec 27, 2003)

OK so aside from cooling, wouldn't driving around at part throttle put more stress on the engine than driving at full throttle? My craftsman throttle isn't all that responsive. If I lower the rpm's about 1/4 of the way down from full it still drives but slows down alot. I think it would be better at full and a lower gear. My bolens which is only 10hp runs almost the same speed at 3/4 or full but I'm not sure it's a good thing to do. Anyone have long term experience with this in both ways? Did your engine last longer because of how you ran it? Do you feel it failed prematurely because of how it was run? Does anyone have real high hours w/o any rebuild or engine work other than maintenance? If so, how are using it? And does anyone have low houurs that even though maintained failed earlier than expected?


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## ducati996 (Dec 27, 2003)

Hi Sixchows,

i still haven't recovered on how you flogged me publicly regarding this topic....deep therapy will take some time to recover 

 


ducati


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## Ed_GT5000 (Sep 30, 2003)

Manufactuers recomend that you run at WOT for cooling and HP. THey base their recomendations on the DESIGN of the engine and the machine.

I Feel this way about the whole thing: 

Every engine or machine that has rotating shafts with gears or pullies will have a "sweet spot" where the mach. will provide ample power and minimal vibration. Indeed, you can take two identical machines and they will perform slightly different at a given RPM.

Remember that the factory recomendations are guidelines, they are not written in stone.

I feel that it is up to the operator to find the rpm that best suits the job that the mach is doing. This is why throttles are put on tractors. 

Furthermore, companies (craftsman) tried making walk behind mowers that did not have throttles and they were unpopular.

For mowing I run WOT or slightly under. For plowing I found a little less throttle worked best.


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## jodyand (Sep 16, 2003)

I still have to degree with some of ya ll sixchows I'm using your picture as an example if you have an older model then it might be OK because the motor is not enclosed so its still able to have the wind blow on it and it may not run as hot.

<img src=http://www.hpphoto.com/servlet/LinkPhoto?GUID=61d72c54-5d88-4b9e-3871-5d702e7f54fa&size=>


And if you have a newer model then the only air you have is whats coming in though the top. And if the motor isn't running WOT then you are not pulling in enough air and it will run hotter. sj I'm using your as an example.
Jody


<img src=http://www.hpphoto.com/servlet/LinkPhoto?GUID=15001924-17a7-17c9-1d0a-4f6644ff53e6&size=>


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## guest2 (Dec 27, 2003)

Ducatti,
Hey I'm sorry you took it that way! Didn't mean it like that at all. But I'm just trying to understand it. That cub looks real nice and thought you wouldn't intentionally cause it any harm.(unless looking for a way to convince the wife you need a new one). That's why I asked where did you get the idea to lower the rpm's as all my manuals recommend WOT. Wasn't trying to say you couldn't read or anything just thought maybe youu had some insight to share. Also, I find that here we seem to get real honest and helpful answers from more intelligent people. Over "there" is more llike a free for all in the sandbox!
Bob
PS
What does your therapist look like maybe you should thank me?LOL


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## guest2 (Dec 27, 2003)

Jody
That makes sense except the other issue might be that the old one (mine) has splash lubrication while the simplicity would be pressure. Would still be interesting to hear from the high hour guys.


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## johnray13 (Oct 30, 2003)

> _Originally posted by Ed_GT5000 _
> *...Every engine or machine that has rotating shafts with gears or pullies will have a "sweet spot" where the mach. will provide ample power and minimal vibration... *


Basically, they're just like a woman. Find that 'sweet spot' and keep them happy.:smiles:


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## Ed_GT5000 (Sep 30, 2003)

I wasn't Thinking about it in that way, but you are right, tractors are a lot like women. :smiles: :smiles: :smiles:


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## guest2 (Dec 27, 2003)

Like Rodney Dangerfield says about cars, " that's why they say she's a beauty, because how many times on a cold winter's morning when you really need it she won't turn over"


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## ducati996 (Dec 27, 2003)

Sixchows,

Out of curiosity your name based on the Chow dog?

my manual states nothing of throttle range to use, so i base it on how it sounds....mowing I'm pretty much full all the time...
In winter its less of a problem, and it appears the blower requires less power than the mower...a lot less even on the deep wet stuff
but I will keep the throttle higher going forward...

Ducati


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## guest2 (Dec 27, 2003)

Ducati,
Yes chow dogs, six of them. 3males, 3 females keeps life interesting especially since the males can't get along. I have the mother and father, and the kids now 2yrs old. The mother can be with any of them but the sons will fight each other and the father would kill any of them except the mother. The daughters will fight each other also.
What engine is in the cub? I would have thought cutting grass would be easier because you probably cut more often. Maybe your throttle cable and carb are more responsive than mine. Mine is like a lawn mower almost, either full run or idle. I've tried adjusting the cable in the past but if I come 1/2 way down on the throttle it just about dies, that's why I couldn't understand it driving and blowing at 3/4.


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## ducati996 (Dec 27, 2003)

Chows are cool dogs, and they are aggressive little buggers thats for sure..I really hope they dont hurt each other...

I have the 20 hp Kohler Command pro...the new ones have the 23 hp version.

i have the full range of throttle from idle to WOT...i will run it more WOT on the next snow removal....no big deal i guess

Ducati


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## guest2 (Dec 27, 2003)

Ducatti
How is your cable set up a lever on the dash? I'd really like to get the full range also, maybe try again in the warm weather.

As for the dogs, They are kept in pairs, so it's almost like having 3. The mother and father, have most of the house, and each set has their own room and don't have any contact with the others except for the mother. All are alternated for yard time throughout the day. They are extremely well cared for and would never be put in harms way. That's pretty much the reason for keeping the pups. We rescued the father, from a dangerous situation running in traffic and couldn't find his owners. Next day we found he had a choker chain embedded in his neck and a serious infection, and seemed to have been abused badly. Tried to place him with a chow rescue service but they already had too many unadoptable aggresive chows. It was either keep him and deal with his aggression,put him to sleep, or left him live the rest of his life in a cage at an animal shelter. Decided to keep him and treat him like a loaded gun. After 5yrs and much effort he is truly a part of the family. A slight miscalculation in the heat cycle led to 4 pups. At 6weeks old one of the males went after the vet and one of the females actually bit the vet, so it seemed like these would also turn out like the father. Needless to say, all are fixed and live here. Here's a pic of mom and pop(OJ black male, Nala)


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## guest2 (Dec 27, 2003)

OK here's the pic?


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