Have your typical 20 horsepower twin cylinder Briggs and Stratton engine mounted in the Sears Craftsman lawn mower.

I have heard different viewpoints on running these engines.......some say to run the engine "wide open" since it has a governor, it lets more air into the engine with the increased RPM's, and more gas is also let in (which also acts as a coolant).

I can't seem to run it like this.  I run the engine up to where it isn't "bogging down", maybe something like 3/4 throttle, and use it like that.  

What are your thoughts?  Thanks.

vmax84

I run it at full throttle so that the blades spin at the proper speed to effectively cut my yard.

Full throttle to work, then idle to empty bags, get a drink, etc. Warm up slowly too. Crank on choke setting, then to idle once running. I let my mower warm two minutes or so before full throttle and applying a load. Planerench.

Quoted: I run it at full throttle so that the blades spin at the proper speed to effectively cut my yard.

I've heard that one as well.  I keep the blades razor sharp and cut the grass often, so "bogging down" really isn't an issue.  

I'm simply wondering what is the best thing for the engine and getting maximum life out of it.

I don't run my car engine wide open...............trying to figure out why I would run the mower wide open.  

Thanks.

vmax84

Scent back

My Srars mower has a small notch in the throttle which puts it at optimal running speed.

Quoted: snip... vmax84

About your car, this is true, but you also have to look at what each one is engineered to do. I think the best thing you can do to prolong your mower's life is keep the blades sharp, fresh oil in it (I change mine after every 50 hours), and maintain it better than you normally would.

If I run my throttle all the way up, it engages the choke.  So I run it up until that point.

Scott

I usually let mine idle at the lowest possible speed, but when I am ready to engage the mower, I crank up the idle until the speed match the little PTO 540 arrow to get the proper blade speed.

Dan

Quoted: Quoted: snip... vmax84 About your car, this is true, but you also have to look at what each one is engineered to do. I think the best thing you can do to prolong your mower's life is keep the blades sharp, fresh oil in it (I change mine after every 50 hours), and maintain it better than you normally would.

I guess sitting on the rider promotes too much idle time in my brain and started to wonder what speed the engine is the happiest at.

But have to agree, changing the oil often and keeping the air filter clean are easy to do and add a lot of life to the engine.

vmax84

My John Deere LT180 owners manual says to run at full throttle for grass cutting.  I also have the 42F mulching deck so you can never have too much power for mulching. when i am just driving around yard with cart, etc. i usually set it about 1/2 throttle.  it does use a bit of gas at full.

What does your mower manufacturer say?

Mine says full throttle to mow.

Wide ass open!

Warp speed!

All the way!

Pedal to the metal!

Full throttle!


You get the point.

Quoted: What does your mower manufacturer say? Mine says full throttle to mow.

Forgot about the manual!!!!  Thanks.  

vmax84

I prefer to run the throttle about 3/4's full capacity and set the deck height about 3" off the ground.  Running in 4th gear (I have 7 on my mower) and the yard always looks real nice.  I mow every 7-10 days in the summer.

lawdog

I am running a John Deere 318 with 1156 hours on it. I run it wide open and service it 2 times a year. Runs great!!

WOT...


Wide Open Throttle

I found out that with some mowers, like my old John Deere, you can actually lift up the clutch/brake pedal with the toe of your shoe, and get an extra little bit of power (for those timed mowings or lawnmower races).

I run mine at 90% powers while mowing.

My John Deere operating manual says to run it wide open. I reduce the rpms when stopped (moving toys, getting another beer, unloading leaves, etc.)

Bomber

Full throttle on mine engages the choke, but there's a definite click in the throttle when that happens, so I ride it there.

My front yard has a 15 degree slope so I need all the power I can get.

I have killed several cheap or free riding mowers and most had the manual with them when someone gave them to me.  All said wide open for mowing.

I have had 2 commercial exmark mowers, one now and one in high school about 15 years ago.  Both say wide open for mowing.

On some mowers the choke is seperate from the throttle.  In this case the choke is off all the way and the throttle is moved to the max it can physically move too.

On one craftsman mower I have, blown up though, it has the choke at the extreme end of the throttle lever range of movement so after starting it I back it down to the notch everyone is talking about for mowing.

For pulling a cart or slowly moving the mower I sometimes use part throttle but one thing to keep in mind with most mowers is that they have a simple oil pressure system.

If you have an oil filter then you actually have an oil pump and are not going to have oil starvation at lower rpms under load.

With some of the older 12.5 horsepower biggs and strattons that came in some sears mowers they are splash lubricated to engine rpm helps lubricate things when under a load.

For the most part I will let a mower idle for a minute or two to cool down and then I shut it down.  They are not really well made for idling for long periods of time and I don't feel they are made to run at less than full throttle in most cases.

I guess I consider them to a generator, it does its max output at max rpm and a mower is made to mow so it is made to mow at max rpm.

My Sears has a notch, so I pretty much always have the throttle there.  That is really close to WOT.

Quoted: I run it at full throttle so that the blades spin at the proper speed to effectively cut my yard.

+1 blade speed is essential.

Air cooled engines are best ran wide open to keep it from overheating.

Some of you guys don't know about heat so you may get away with it!

Use your transmission to determine the speed you are going.

BigDozer66

Quoted: Quoted: I run it at full throttle so that the blades spin at the proper speed to effectively cut my yard. I've heard that one as well.  I keep the blades razor sharp and cut the grass often, so "bogging down" really isn't an issue.   I'm simply wondering what is the best thing for the engine and getting maximum life out of it. I don't run my car engine wide open...............trying to figure out why I would run the mower wide open.   Thanks. vmax84

Your car is liquid cooled so it is a completely different engine set up.

BigDozer66

Quoted: Wide ass open! Warp speed! All the way! Pedal to the metal! Full throttle! You get the point.

Git 'r done!

BigDozer66

21hp Intek B&S, here. Manual says wide open when running PTO *shrug*

I wonder if I drink too much beer while mowing.  

vmax84

All of the garden tractors I have had recommended running wide open, the engine is governed to run at the most efficient RPM, so it's not actually at the highest RPM possible with the engine.

WOT.  

It's designed for it, and your power attachments are designed for full power as well.  

25 hp is NOT too much with a 48" cutting deck or a 42" snow thrower, but it does use some fuel.  

Wide open unless I'm off the thing to load somethig or move something out of the way.  I turn it off rather than let it idle for more than a minute or so.  

And, Kohler recommends letting it idle down after running it at WOT before shutting it off so it won't backfire.  It will backfire if you don't.