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I want to buy a new small rotary motor mower of about 18 to 24 inch cut. Grass box not essential as I mulch mow.

But I want a quiet one. Years ago, the long stroke mowers reved slower and were quieter. One modern one I can hear from 1/4 mile away is a Honda, which put me off that make.

I have never seen the noise of mowers compared but they all seem to have a decibel label attached.

Sometimes it is not so much the volume of noise but the frequency. A low pitch mower is more tolerable than a high pitched one. Is there a special specification for mowers used around Hospitals etc?

Does anyone know of a particularly quiet model? I prefer 4 stroke.

I am in the UK.

Ah, in the UK. Well this makes things easier!

I own a Mountfield SP414 (On sale in B&Q for ｣159.99), which has a sticker on it saying it produces 96DB noise levels, however it isn't a high pitched engine.

It is a bit like a V8 kind of sound actually :laughing:

The Mountfield SP414 also leaves the grass looking like it has been mowed with a cylinder mower, so I've got no complaints on the quality of the lawn. The body is polypropylene which means it won't rust, neither will it crack. The engine is a 100CC RS100 engine, made by Mountfield, which starts on the first pull after three primes of the bulb, and runs nice and smooth.

You will always have the engine noise with an internal combustion engine. Some makes use a better muffler system than others...
The type of grass you cut can have an impact, If you do not need a high lift blade, you can use one that is closer to flat... the less pitch a blade has the quieter it will run...

Also if you keep the blades very sharp you can reduce the engine RPM & that will have an impact on sound levels... :smile:KennyV

KennyV said:

You will always have the engine noise with an internal combustion engine. Some makes use a better muffler system than others...
The type of grass you cut can have an impact, If you do not need a high lift blade, you can use one that is closer to flat... the less pitch a blade has the quieter it will run...

Also if you keep the blades very sharp you can reduce the engine RPM & that will have an impact on sound levels... :smile:KennyV

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That is very true, but new engines don't have throttles, so that wouldn't matter :frown:

jmurray01 said:

That is very true, but new engines don't have throttles, so that wouldn't matter :frown:

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I did not realize you didn't have them... The only fixed rpm engines over here are usually found on generators, and even they have the ability to change the rpm...

Well I guess I should say... The engines I am aware over here, all have variable throttles....

So your mowers are either running "full on" or they are OFF. That's very interesting... :smile:KennyV

Several push mowers don't have a throttle but I don't think I ever saw a riding mower without a throttle.

Black Bart said:

Several push mowers don't have a throttle but I don't think I ever saw a riding mower without a throttle.

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I've seen some with no throttle on the handle, near the operator...
But they all had a throttles settable at the carb, allowing you to set the engine speed...

I guess I need to get out more & see what is 'not' available any longer... :smile:KennyV

When I see / hear "rotary motor - rotary engine" I think Wankel !

Wondering if "rotary motor" means the same as "vertical shaft" ???

Bam said:

I want to buy a new small rotary motor mower

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BKBrown said:

...
...
Wondering if "rotary motor" means the same as "vertical shaft" ???

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I think today it most likely is interchangeable, But back in the early 60's or late 50's Snapper had a monster self propelled, commercial grade rotary mower... With a BIG horizontal shaft Wisconsin engine... :smile:KennyV

Thanks for your responses. I did not expect to get such a quick reply. This is a great forum. The Mountfield mower sounds a good buy but I think I would be looking for a larger size if they do one. I am starting to feel a bit of old age and the smallest budget mower I have now takes an age to do my grass which is quite a large area for a push along mower but has too many nooks and crannies for a ride on and anyway I need the workout !

I am wondering if a dedicated mulch mower might be the quieter option because they do not have to generate a "vacuum cleaner" fan effect to blow the grass into a box .

I think I am safe in saying that Mountfield do not make engines although their name may be on them. Probably use a Chinese engine or from Poland or some such place.

I was always keen on the Briggs and Stratton sidevalve motors ( flathead to you Yanks). They had a slow reving engine which sounded nice and had a lot of torque ( ie difficult to stall ) and they would outlast the rest of the mower. However, they now use a shorter stroke engine, which has to rev more for the same power and they have devised a troublesome carburettor set up. The last two engines were OK new but after a couple of years developed the same fault of reving faster and faster when they get hot and there is no problem with the govenor mechanism. This also causes them to gobble fuel (very expensive in the UK). I think it maybe that they use a horrible membrane type carb.

Someone mentioned the Wankel engine and a V8 but I only want to cut grass not go mower racing :laughing:

With fuel being extensive in the UK... are there any diesel powered small mowers there?
With diesel you have a lower rpm engine with high low end torque, and very fuel efficient...

You are well ahead of the States on public acceptance of diesel powered vehicles. I would expect there to be various models using the advantages of diesel....
I know there are single and two cylinder diesel engines, are there any on popular mowers? :smile:KennyV

KennyV said:

With fuel being extensive in the UK... are there any diesel powered small mowers there?
With diesel you have a lower rpm engine with high low end torque, and very fuel efficient...

You are well ahead of the States on public acceptance of diesel powered vehicles. I would expect there to be various models using the advantages of diesel....
I know there are single and two cylinder diesel engines, are there any on popular mowers? :smile:KennyV

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Diesel is always more feasible with large engines. Small diesels do exist but are heavier, more noisy, smelly and difficult to start than a small petrol unit and not suited to small applications. Fuel efficiency is not so important with a small mower but I notice that the Briggs & Statton use a lot more fuel than the same size Chinese engines. Diesel fuel is more expensive than petrol in the UK but often cheaper in parts of Europe. It has something to do with refining capacity I think. In theory diesel should be cheaper because it requires less refining but most of our fuel price is tax.

What we do use more and more is a fuel made from the waste oil from deep fryers in restaurants. This works well in diesel cars but they smell of potato chips. A lot of van drivers also buy and use fresh cooking oil because it is has no tax on it and some of our food stores sell it in 5 gallon drums. But the drivers are fined if it is found in their fuel tanks.

When I was in America this year folk were boasting if their cars could do 30 miles per gallon. Over here we look for one that does 50 or 60 miles per gallon, which is possible with a good diesel.

Bam said:

Diesel is always more feasible with large engines. Small diesels do exist but are heavier, more noisy, smelly and difficult to start than a small petrol unit and not suited to small applications. Fuel efficiency is not so important with a small mower but I notice that the Briggs & Statton use a lot more fuel than the same size Chinese engines. Diesel fuel is more expensive than petrol in the UK but often cheaper in parts of Europe. It has something to do with refining capacity I think. In theory diesel should be cheaper because it requires less refining but most of our fuel price is tax.

What we do use more and more is a fuel made from the waste oil from deep fryers in restaurants. This works well in diesel cars but they smell of potato chips. A lot of van drivers also buy and use fresh cooking oil because it is has no tax on it and some of our food stores sell it in 5 gallon drums. But the drivers are fined if it is found in their fuel tanks.

When I was in America this year folk were boasting if their cars could do 30 miles per gallon. Over here we look for one that does 50 or 60 miles per gallon, which is possible with a good diesel.

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Heck, our 1997 Ford Fiesta 1.25i Ghia does 45-50MPG, and it is a petrol! Think what a diesel of the same size would do ? Could be nearer 100!

jmurray01 said:

Heck, our 1997 Ford Fiesta 1.25i Ghia does 45-50MPG, and it is a petrol! Think what a diesel of the same size would do ? Could be nearer 100!

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Ok JMurray. You are driving carefully to get that, well done. The old Minis did about the same and the Metro petrol would do over 50 mpg with care. I have a Mazda 1.3 and on a gentle road and driven with great care and little traffic I can squeeze 50 but I had a Metro diesel and you could drive it any old how and get 60 mpg. However the Yanks would consider our cars as pedal cars !!

This was one not uncommon style of vehicle I spotted in Miami:

Kenny, I know there are rotary mowers with horizontal shaft engines, PTO shafts, and even Hydro drive. I was talking about a rotary motor reminding me of Wankel Engines -- (I believe Mazda still uses them in some of their cars.)

KennyV said:

I think today it most likely is interchangeable, But back in the early 60's or late 50's Snapper had a monster self propelled, commercial grade rotary mower... With a BIG horizontal shaft Wisconsin engine... :smile:KennyV

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BKBrown said:

[COLOR=blu
... I was talking about a [B]rotary[/B] motor reminding me of Wankel Engines -- (I believe Mazda still uses them in some of their cars.)[/COLOR]

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Ah-ha you are right... It has been a while since I've come across a Wankel engine... I use to see them every now and then... :smile:KennyV