Run at Full Throttle?

[toolboxhero]

Running full throttle gives you the proper bade tip speed so the mower will cut at its best. That's one of the reasons push mowers no longer have a throttle - too many people complained that the mower wouldn't cut well. It was because the mower was too loud at full rpm so they would throttle the engine down to reduce the noise and then complain the mower didn't cut well.

 

[StarTech]

Personally I think it was a cost cutting by the manufactures as consumers just demanding lower cost equipment. There was one push mower engine setup by Briggs that would auto idle and then power up when it ran into a load. A very picky engine for its governor spring had to be the correct one or the engine would overheat.

 

[peejo50]

I like all the input about throttle position and made it made me wonder about non-hydro tractors. I have some older equipment that have Kohler K-series engines. Full throttle in 3rd gear is sometimes too fast and in 2nd gear it's too slow, so I use the throttle to adjust my speed. I'm not always using these tractors to mow but for other chores. Bad idea?

 

[Mattmotors]

Being older, I prefer an engine that is quiet. It would really be nice if a manufacture could make a quiet engine. I took the ear plug route. Full throttle. Cool engine.

 

[barny57]

Wide open throttle.
Period.
Do some additional research and reading as to why if you are interested. Older men are notorious for running equipment at say 3/4 throttle.

That’s me, maybe lucky but never had a problem one of my J D is 41 years old

 

[lowmow]

Air flow is not linear with speed.Double the speed,and you cube the air flow,so higher speed gives a much higher air flow than low speed,and the engine will run cooler,even though the engine is producing more heat,overall,the engine and oil are cooler.
The old air cooled beetles could run from coast to coast in 2nd gear,pedal to the metal and not overheat,but don't lug the engine at low speed,same with the old Porches.
Most diesels are also designed to run wide open throttle also.
Lugging a diesel is a death sentence for longevity.Truckers know this.
I am an old timer,and I have had a 16HP Briggs single cylinder MTD garden tractor since 1979.It was sold by JC Penny as a Model 1853,but made by MTD before they had their own brand.
Hydrostatic drive,hydraulic lift(Converted to 3 point cat 0 hitch by me.Replaced the front axle spindles with boat trailer axles and Bearing Buddies,no other problems since,and I hardly ever ran it at full throttle.Must have been a different fan design back then.
Some progress isn't progressive.

 

[thesilentone]

On many new pieces of equipment the ' Certificate of Conformity' can dictate engine speed. irrespective of performance.

If the equipment exceeds any of the following: Noise, Emissions, HAV (hand are vibration) or WBV (whole body vibration) the easiest solution is to reduce engine speed to a level where it does conform.

That is why, after purchasing a new piece of kit you find you need to set the engine revs higher, or remove a throttle stop that has been added to gain the performance level that is satisfactory.

 

[Laabk2]

Another reason to run at full throttle is that the alternator is designed to produce the required voltage to recharge and maintain the battery at that RPM. I have replaced many batteries because the mower wouldn't start after a month or two of mowing with a new battery installed. I got it running and then asked them to try it out, they hopped on, cranked it up and took off mowing at 1/2 to 3/4 throttle. I explained the whole RPM to charging concept. I got a deer in the headlight look and they said ok. Couple of months later, battery replaced again. Some people just refuse to listen and enjoy spending money.

 

[DinosaurMike]

From your original post: "According to the owner's manual, the engine should be run at the fast setting of the throttle, a/k/a full throttle, wide open." Period. End of answer. That is all you need to know. <You should apply for a job with Cub Cadet (MTD?) if you think you know more than the engineers. LOL>

 

[grumpyunk]

If you run at slower rpms, the cooling effect of oil being splashed everywhere is reduced. You may starve parts of lubrication they would get at full operating rpm. Additionally, the cooling of the flywheel blower is also reduced at lower rpm. Does lower rpm produce less heat? Probably. Does the blower produce less airflow? Definitely. The higher rpms are designed into the engines, so do what you will, but there is a detent in the throttle control that was also designed into the machine.
They were not designed to be 'babied' which a lot of us like to do. I was 'babying' my Kohler, running @3/4 throttle to be 'nice' to my engine. Wrong. It likely didn't hurt it permanently, but continued running at lower rpms and lowering for the run back to the shed are not really good ideas, and are likely not recommended by the manufacturer. As a matter of fact, some recommend to not lower the engine control/rpms prior to killing the ignition. Suspect it has to do with back fire/back fire out the exhaust.
Have fun.
tom