GearHead36
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^ This. I think this is why my riders give a better cut than my walk behinds.
RPM for a 22" residential push mower
- Thread starter GearHead36
- Start date
I watched three videos this guy did on balancing using an oscilloscope. I'm definitely going to try this one and maybe work my way up to a wheel balancer for my motorcycles.
www.youtube.com/watch?v=r6tFXC4Hk0I
www.youtube.com/watch?v=r6tFXC4Hk0I
What brand tach are you using? I too feel like my mower is too slow. Can an old v8 tach from the 60s be used?
rutbuster1
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This guy, Taryl Fixes All, and Chickanic are all good. Taryl cracks me up..........js
GearHead36
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This one. I don't know about the v8 tach.
7394
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Good tach should have a place to select how many cylinders it is timing.
You're going to get a whole lot of opinions on this, even more so than the correct way to sharpen a blade or whether new blades should be sharpened. LOL
I have done thousands of these mowers and I can tell you it's irrelevant what the spec is from the factory or what they claim they set them at because even out of the box they are so inconsistent it is absolutely pathetic.
It does no good to have a spec if you don't set things at spec.
Now a lot of the older guys are going to claim even higher speeds because a lot of these engines used to be rated at 3600 RPMs and you could even run them at that because the blades were shorter and if you go back far enough there were no legal requirements or maximum tip speeds.
The vast majority of these Toros come out of the box at 2880 or that's what my digital tach shows and what the last one showed too so maybe it's supposed to be 2850 or 2900 but my tach always gets stuck right at 2880. Lol
I said all the self-propelled ones at 2880 and I've also noticed that a lot of the cheaper push mowers come with a little bit higher RPMs so I tend to follow suit and put them right around 2950 to 3,000 or even 3050.
There's really little need to have these mowers at 3200 or faster because frankly, you're just wasting fuel and wearing out Parts a little bit more quickly and on a lot of them it makes the self-propelled kind of dragging you and trying to cut the grass too quickly.
Of course this varies when you have the personal pace versus the metal bail that you squeeze but you typically end up having to modulate the more manual style ones to keep the speed where you really want it to be of the drive and the cut.
Anything down around 2600 starts to become a little anemic.
I have found that 2880 works perfectly for the Toro 22-in self-propelled mowers.
If you're having a vibration issue then it's not the engine speed at all.
It either has a bent blade or likely it's had a blade strike and the crankshaft is slightly tweaked.
While it is true that normally a vibration is worse at higher speeds it's not always the case because of crazy harmonics and stuff we can't nearly comprehend, visualize or it really tests without equipment well beyond the scope any of us have.
Sometimes 200 RPMs one way or the other will make a noticeable difference and smoothness so play around with it some.
MORE importantly try to clock the blade one half turn around.
On most mowers you have the standard position and then you can rotate it 180° to do it in that position but some of the mowers with the Stars have five different positions you can put them on.
If someone would have told me before I start with my own eyes that rotating a blade 180° out or even one or two notches on a star pattern could make such a difference a vibration between daylight and dark I would have bet them $100 there's no way!
I would have lost $100!!
In fact I've shown a number of people this in person because it always astounds them..
It's not always the case but when conditions are just right and the crankshaft is tweaked in some certain way, a brand new blade, used one etc can be placed on one way and the vibrations can be so much you can barely stand to hold the handle but rotate the blade around 180° and no one could ever tell it had a blade strike or a bent or twisted crank.
So the takeaway from this is anytime you have a vibrating mower always try the blade in both or multiple positions to test it out to see which way is the smoothest.
Ask someone else missing, balancing on a nail stuck in the wall is more than you'll ever need to balance a lawn mower blade.
You are rarely get one that's severely out of balance and most the time they will hang level or maybe just two or three inches low on one side of the other or have a tendency to go down on one side which you can find tune by taking some metal off that side but when you actually get one that's out of balance soon as you put it on the nail one in will point straight to the ground!
All you have to do is basically get it in the center of the hole when you set the blade on the nail and then see where it goes.
It really isn't rocket science and this is quite accurate enough.
I have done thousands of these mowers and I can tell you it's irrelevant what the spec is from the factory or what they claim they set them at because even out of the box they are so inconsistent it is absolutely pathetic.
It does no good to have a spec if you don't set things at spec.
Now a lot of the older guys are going to claim even higher speeds because a lot of these engines used to be rated at 3600 RPMs and you could even run them at that because the blades were shorter and if you go back far enough there were no legal requirements or maximum tip speeds.
The vast majority of these Toros come out of the box at 2880 or that's what my digital tach shows and what the last one showed too so maybe it's supposed to be 2850 or 2900 but my tach always gets stuck right at 2880. Lol
I said all the self-propelled ones at 2880 and I've also noticed that a lot of the cheaper push mowers come with a little bit higher RPMs so I tend to follow suit and put them right around 2950 to 3,000 or even 3050.
There's really little need to have these mowers at 3200 or faster because frankly, you're just wasting fuel and wearing out Parts a little bit more quickly and on a lot of them it makes the self-propelled kind of dragging you and trying to cut the grass too quickly.
Of course this varies when you have the personal pace versus the metal bail that you squeeze but you typically end up having to modulate the more manual style ones to keep the speed where you really want it to be of the drive and the cut.
Anything down around 2600 starts to become a little anemic.
I have found that 2880 works perfectly for the Toro 22-in self-propelled mowers.
If you're having a vibration issue then it's not the engine speed at all.
It either has a bent blade or likely it's had a blade strike and the crankshaft is slightly tweaked.
While it is true that normally a vibration is worse at higher speeds it's not always the case because of crazy harmonics and stuff we can't nearly comprehend, visualize or it really tests without equipment well beyond the scope any of us have.
Sometimes 200 RPMs one way or the other will make a noticeable difference and smoothness so play around with it some.
MORE importantly try to clock the blade one half turn around.
On most mowers you have the standard position and then you can rotate it 180° to do it in that position but some of the mowers with the Stars have five different positions you can put them on.
If someone would have told me before I start with my own eyes that rotating a blade 180° out or even one or two notches on a star pattern could make such a difference a vibration between daylight and dark I would have bet them $100 there's no way!
I would have lost $100!!
In fact I've shown a number of people this in person because it always astounds them..
It's not always the case but when conditions are just right and the crankshaft is tweaked in some certain way, a brand new blade, used one etc can be placed on one way and the vibrations can be so much you can barely stand to hold the handle but rotate the blade around 180° and no one could ever tell it had a blade strike or a bent or twisted crank.
So the takeaway from this is anytime you have a vibrating mower always try the blade in both or multiple positions to test it out to see which way is the smoothest.
Ask someone else missing, balancing on a nail stuck in the wall is more than you'll ever need to balance a lawn mower blade.
You are rarely get one that's severely out of balance and most the time they will hang level or maybe just two or three inches low on one side of the other or have a tendency to go down on one side which you can find tune by taking some metal off that side but when you actually get one that's out of balance soon as you put it on the nail one in will point straight to the ground!
All you have to do is basically get it in the center of the hole when you set the blade on the nail and then see where it goes.
It really isn't rocket science and this is quite accurate enough.
aussielawny
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Trying to balance with a nail is as useless as not bothering at all
You can tell yourself that, or think it, or tell as many people as you want but it won't be true.
Balancing a 22 inch lawn mower blade on a nail hanging in the wall is more than accurate enough for this type of equipment!!!
These mowers are used in often quite poor conditions and abused and the blades are very neglected.
They tend to be quite forgiving.
It's rare to find a lawn mower or at least there's a high percentage of them where when you rotate the blade around and Mark a spot on the deck and then rotate it around 180° to check, they are not lined up anyways.
This is often dude to slightly bent blades and also due to vent or ideally more accurately twisted crankshafts.
The reasons really don't matter but the current condition does.
My lawn mower blade can be quite out of balance and you still won't notice any increase vibrations on the handle but a crankshaft can be bent just a little bit to where it's barely visible which is far more bent than what a dial indicator would show you and it can vibrate like mad.
He can also have an extremely visible wobble and deflection from being perfectly straight, round, concentric, or whatever you want to call it in high tech engineering or machine shop terms... And it can be so smooth no one would ever tell there's any increased vibration on the handle.
It's not an exact science and there are some weird things that happen.
Regardless, if a blade is badly out of balance when you stick it on a nail the heavy end will turn and point straight to the ground..
Anything even close to hanging horizontally is fine for lawn mowers.
Worrying about anything else beyond this is simply applying some aspect of OCD to it, being pedantic, or making a mountain out of a molehill.