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Default Importance of lawnmower governor?

My spare lawnmower, a Mountfield, B+S engined SP470 is playing up.
It is revving and slowing, revving then slowing etc.

It is all related to the governor springs/fan, which slow it down when
it is revving too much.
Now this wouldnt be a problem if they work, and are easy to adjust, but
they rarely work properly, and are a pain to adjust - approx 10 mins for
each adjustment.
So I had an idea of doing away with the governor altogether and attching
a throttle cable to the linkage, to adjust engine speed that way. This
engine has no throttle adjustment, when under load, the governor is
meant to adjust it to give a constant RPM.

So , the query is - is it viable to do away with the governor and
control the engine speed manually?
Thanks
Alan.


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Default Importance of lawnmower governor?

A.Lee wrote:
My spare lawnmower, a Mountfield, B+S engined SP470 is playing up.
It is revving and slowing, revving then slowing etc.

It is all related to the governor springs/fan, which slow it down when
it is revving too much.
Now this wouldnt be a problem if they work, and are easy to adjust, but
they rarely work properly, and are a pain to adjust - approx 10 mins for
each adjustment.
So I had an idea of doing away with the governor altogether and attching
a throttle cable to the linkage, to adjust engine speed that way. This
engine has no throttle adjustment, when under load, the governor is
meant to adjust it to give a constant RPM.

So , the query is - is it viable to do away with the governor and
control the engine speed manually?


Yes, but he main problem is that you will be constantly fiddling was it
runs into different loads.

It sounds like you have some friction in the governor..not just
maladjustmemnt.



Thanks
Alan.


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Default Importance of lawnmower governor?


The Natural Philosopher wrote in message
...
A.Lee wrote:
My spare lawnmower, a Mountfield, B+S engined SP470 is playing up.
It is revving and slowing, revving then slowing etc.

It is all related to the governor springs/fan, which slow it down when
it is revving too much.
Now this wouldnt be a problem if they work, and are easy to adjust, but
they rarely work properly, and are a pain to adjust - approx 10 mins for
each adjustment.
So I had an idea of doing away with the governor altogether and attching
a throttle cable to the linkage, to adjust engine speed that way. This
engine has no throttle adjustment, when under load, the governor is
meant to adjust it to give a constant RPM.

So , the query is - is it viable to do away with the governor and
control the engine speed manually?


Yes, but he main problem is that you will be constantly fiddling was it
runs into different loads.

It sounds like you have some friction in the governor..not just
maladjustmemnt.


Or it is running very weak (fuel mixture)



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Default Importance of lawnmower governor?

On 8 Aug, 22:49, "Mark" wrote:
The Natural Philosopher wrote in ...
A.Lee wrote:


My spare lawnmower, a Mountfield, B+S engined SP470 is playing up.
It is revving and slowing, revving then slowing etc.


It is all related to the governor springs/fan, which slow it down when
it is revving too much.
Now this wouldnt be a problem if they work, and are easy to adjust, but
they rarely work properly, and are a pain to adjust - approx 10 mins for
each adjustment.
So I had an idea of doing away with the governor altogether and attching
a throttle cable to the linkage, to adjust engine speed that way. This
engine has no throttle adjustment, when under load, the governor is
meant to adjust it to give a constant RPM.


So , the query is - is it viable to do away with the governor and
control the engine speed manually?


Yes, but he main problem is that you will be constantly fiddling was it
runs into different loads.


It sounds like you have some friction in the governor..not just
maladjustmemnt.


Or it is running very weak (fuel mixture)


yes, much more likely.

NT

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Default Importance of lawnmower governor?

On 8 Aug, 18:20, (A.Lee) wrote:
My spare lawnmower, a Mountfield, B+S engined SP470 is playing up.
It is revving and slowing, revving then slowing etc.

It is all related to the governor springs/fan, which slow it down when
it is revving too much.
Now this wouldnt be a problem if they work, and are easy to adjust, but
they rarely work properly, and are a pain to adjust - approx 10 mins for
each adjustment.
So I had an idea of doing away with the governor altogether and attching
a throttle cable to the linkage, to adjust engine speed that way. This
engine has no throttle adjustment, when under load, the governor is
meant to adjust it to give a constant RPM.

So , the query is - is it viable to do away with the governor and
control the engine speed manually?
Thanks
Alan.

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To reply by e-mail, change the ' + ' to 'plus'.


I had exactly the same problem on mine so I removed the governor and
attached the throttle direct.

It does work... BUT.

It's very easy to really rev the nuts off it if you're not careful

It does tend to slow when you cut long grass and speed up for shorter
grass.

All things considered I prefer it without the governor and manage fine
with it.

Good luck
Mike



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Default Importance of lawnmower governor?

Mark wrote:
The Natural Philosopher wrote in message
...

A.Lee wrote:

My spare lawnmower, a Mountfield, B+S engined SP470 is playing up.
It is revving and slowing, revving then slowing etc.

It is all related to the governor springs/fan, which slow it down when
it is revving too much.
Now this wouldnt be a problem if they work, and are easy to adjust, but
they rarely work properly, and are a pain to adjust - approx 10 mins for
each adjustment.
So I had an idea of doing away with the governor altogether and attching
a throttle cable to the linkage, to adjust engine speed that way. This
engine has no throttle adjustment, when under load, the governor is
meant to adjust it to give a constant RPM.

So , the query is - is it viable to do away with the governor and
control the engine speed manually?


Yes, but he main problem is that you will be constantly fiddling was it
runs into different loads.

It sounds like you have some friction in the governor..not just
maladjustmemnt.



Or it is running very weak (fuel mixture)

I had a similar symptoms with a Mountfield which was due to a partially
blocked fuel intake filter.
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Default Importance of lawnmower governor?

The Natural Philosopher wrote:

A.Lee wrote:
My spare lawnmower, a Mountfield, B+S engined SP470 is playing up.
It is revving and slowing, revving then slowing etc.
It is all related to the governor springs/fan, which slow it down when
it is revving too much.
So , the query is - is it viable to do away with the governor and
control the engine speed manually?


Yes, but he main problem is that you will be constantly fiddling was it
runs into different loads.

It sounds like you have some friction in the governor..not just
maladjustmemnt.


No, it is the spring adjustment on the governor. There are 2 springs,
both of which slacken with age, or when messed around with.When viewed
from the side,with the engine running, it is clear that they are too
slack, so I've tightened them slightly, which leads to over revving, so
readjust, and it is too slow etc.
It is a pain to adjust them, as you need to remove the top cover and
starter puller plate to get at them. If they were open, then adjustment
would be a lot easier.
Thanks
Alan.

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Default Importance of lawnmower governor?

A.Lee wrote:
The Natural Philosopher wrote:

A.Lee wrote:
My spare lawnmower, a Mountfield, B+S engined SP470 is playing up.
It is revving and slowing, revving then slowing etc.
It is all related to the governor springs/fan, which slow it down when
it is revving too much.
So , the query is - is it viable to do away with the governor and
control the engine speed manually?

Yes, but he main problem is that you will be constantly fiddling was it
runs into different loads.

It sounds like you have some friction in the governor..not just
maladjustmemnt.


No, it is the spring adjustment on the governor. There are 2 springs,
both of which slacken with age, or when messed around with.When viewed
from the side,with the engine running, it is clear that they are too
slack, so I've tightened them slightly, which leads to over revving, so
readjust, and it is too slow etc.
It is a pain to adjust them, as you need to remove the top cover and
starter puller plate to get at them. If they were open, then adjustment
would be a lot easier.
Thanks
Alan.

New springs maybe?
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Default Importance of lawnmower governor?


"A.Lee" wrote in message
...
snip

No, it is the spring adjustment on the governor. There are 2 springs,
both of which slacken with age, or when messed around with.When viewed
from the side,with the engine running, it is clear that they are too
slack,


Adjustment of governor springs is non-obvious. Download a copy of the
engine manual, if you can, and you may well find that the springs are
designed not to be in tension all the time.


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Kevin Poole
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