On Sat, 27 Apr 2024 17:23:25 -0600, Nick Cine <nickcine@is.invalid>
wrote:

>Took apart the pull mechanism of my single-cylinder Craftsman push lawn
>mower today since it hasn't been used in a year and it wouldn't start in
>one pull and the recoil spring mechanism was not recoiling after the first
>pull (the cord just hung limp).
>
>https://i.postimg.cc/xjzzBZkW/lawnmower.jpg
>
>When I cleaned up the recoil mechanism & put it back together, I found some
>of last year's gasoline, and it worked just fine (so anyone who says you
>can't use old gas is gonna have to explain why it worked just fine for me
>today).
>
>After two or three pulls with the choke locked open (otherwise it slides
>shut too quickly), the motor started and after about ten seconds on choke,
>I removed the clamp I put on the choke lever to keep it in place.
>
>I cleaned out the air filter too and cleaned up old grass in the blade area
>(and a bunch of rope tangled around the driveshaft - I guess slowing down
>the blade is what makes the motor shut off since I defeated the shutoff
>mechanism due to it being a PITA as you always have to hold it on).
>
>Anyway, my question is I started to wonder how the spark is generated,
>and I wondered how a simple (Craftsman) lawn mower advances its timing.
>

youtube can sometimes be your friend.

https://www.youtube.com/watch?v=ckyFlX4CUVU

Old gas isn't _always_ problematic ; very old gas _is_.
In general, spark comes from the coil, activated by the
magnet on the flywheel.
In general, the "governor" is ruled by the fins on the
flywheel - working against a small spring on the flapper
that controls the carb ..
John T.

In alt.home.repair, on Sat, 27 Apr 2024 20:17:46 -0400,
hubops@ccanoemail.com wrote:

>On Sat, 27 Apr 2024 17:23:25 -0600, Nick Cine <nickcine@is.invalid>
>wrote:
>
>>Took apart the pull mechanism of my single-cylinder Craftsman push lawn
>>mower today since it hasn't been used in a year and it wouldn't start in
>>one pull and the recoil spring mechanism was not recoiling after the first
>>pull (the cord just hung limp).
>>
>>https://i.postimg.cc/xjzzBZkW/lawnmower.jpg
>>
>>When I cleaned up the recoil mechanism & put it back together, I found some
>>of last year's gasoline, and it worked just fine (so anyone who says you
>>can't use old gas is gonna have to explain why it worked just fine for me
>>today).
>>
>>After two or three pulls with the choke locked open (otherwise it slides
>>shut too quickly), the motor started and after about ten seconds on choke,
>>I removed the clamp I put on the choke lever to keep it in place.
>>
>>I cleaned out the air filter too and cleaned up old grass in the blade area
>>(and a bunch of rope tangled around the driveshaft - I guess slowing down
>>the blade is what makes the motor shut off since I defeated the shutoff
>>mechanism due to it being a PITA as you always have to hold it on).
>>
>>Anyway, my question is I started to wonder how the spark is generated,
>>and I wondered how a simple (Craftsman) lawn mower advances its timing.
>>
>
>
>youtube can sometimes be your friend.
>
>https://www.youtube.com/watch?v=ckyFlX4CUVU
>
>Old gas isn't _always_ problematic ; very old gas _is_.
>In general, spark comes from the coil, activated by the
>magnet on the flywheel.
>In general, the "governor" is ruled by the fins on the
>flywheel - working against a small spring on the flapper
>that controls the carb ..

That controls the carb, as you say, giving it more gas iirc when the
engine slows. The fins blow less on the flapper/sail which no longer
overpowers the spring, which then pulls the throttle farther open.

But there is no spark advance on a the small lawn mower engines I worked
on. Of course I only substantially took one apart 60 years ago, and
less so 20 years. ago.

> John T.

On 4/27/2024 7:17 PM, hubops@ccanoemail.com wrote:
> On Sat, 27 Apr 2024 17:23:25 -0600, Nick Cine <nickcine@is.invalid>
> wrote:
>
>> Took apart the pull mechanism of my single-cylinder Craftsman push lawn
>> mower today since it hasn't been used in a year and it wouldn't start in
>> one pull and the recoil spring mechanism was not recoiling after the first
>> pull (the cord just hung limp).
>>
>> https://i.postimg.cc/xjzzBZkW/lawnmower.jpg
>>
>> When I cleaned up the recoil mechanism & put it back together, I found some
>> of last year's gasoline, and it worked just fine (so anyone who says you
>> can't use old gas is gonna have to explain why it worked just fine for me
>> today).
>>
>> After two or three pulls with the choke locked open (otherwise it slides
>> shut too quickly), the motor started and after about ten seconds on choke,
>> I removed the clamp I put on the choke lever to keep it in place.
>>
>> I cleaned out the air filter too and cleaned up old grass in the blade area
>> (and a bunch of rope tangled around the driveshaft - I guess slowing down
>> the blade is what makes the motor shut off since I defeated the shutoff
>> mechanism due to it being a PITA as you always have to hold it on).
>>
>> Anyway, my question is I started to wonder how the spark is generated,
>> and I wondered how a simple (Craftsman) lawn mower advances its timing.
>>
>
>
> youtube can sometimes be your friend.
>
> https://www.youtube.com/watch?v=ckyFlX4CUVU
>
> Old gas isn't _always_ problematic ; very old gas _is_.
> In general, spark comes from the coil, activated by the
> magnet on the flywheel.

It's called a "magneto"

> In general, the "governor" is ruled by the fins on the
> flywheel - working against a small spring on the flapper
> that controls the carb ..
> John T.
>

The governor controls only engine speed , has nothing to do with spark
timing - which is static , there is no advance mechanism . Study up John
, it appears you don't actually know how either system works .
--
Snag
"They may take our lives but
they'll never take our freedom."
William Wallace

On Sun, 28 Apr 2024 07:06:47 -0500, Snag <snag_one@msn.com> wrote:

>On 4/27/2024 7:17 PM, hubops@ccanoemail.com wrote:
>> On Sat, 27 Apr 2024 17:23:25 -0600, Nick Cine <nickcine@is.invalid>
>> wrote:
>>
>>> Took apart the pull mechanism of my single-cylinder Craftsman push lawn
>>> mower today since it hasn't been used in a year and it wouldn't start in
>>> one pull and the recoil spring mechanism was not recoiling after the first
>>> pull (the cord just hung limp).
>>>
>>> https://i.postimg.cc/xjzzBZkW/lawnmower.jpg
>>>
>>> When I cleaned up the recoil mechanism & put it back together, I found some
>>> of last year's gasoline, and it worked just fine (so anyone who says you
>>> can't use old gas is gonna have to explain why it worked just fine for me
>>> today).
>>>
>>> After two or three pulls with the choke locked open (otherwise it slides
>>> shut too quickly), the motor started and after about ten seconds on choke,
>>> I removed the clamp I put on the choke lever to keep it in place.
>>>
>>> I cleaned out the air filter too and cleaned up old grass in the blade area
>>> (and a bunch of rope tangled around the driveshaft - I guess slowing down
>>> the blade is what makes the motor shut off since I defeated the shutoff
>>> mechanism due to it being a PITA as you always have to hold it on).
>>>
>>> Anyway, my question is I started to wonder how the spark is generated,
>>> and I wondered how a simple (Craftsman) lawn mower advances its timing.
>>>
>>
>>
>> youtube can sometimes be your friend.
>>
>> https://www.youtube.com/watch?v=ckyFlX4CUVU
>>
>> Old gas isn't _always_ problematic ; very old gas _is_.
>> In general, spark comes from the coil, activated by the
>> magnet on the flywheel.
>
> It's called a "magneto"
>
>
>> In general, the "governor" is ruled by the fins on the
>> flywheel - working against a small spring on the flapper
>> that controls the carb ..
>> John T.
>>
>
>The governor controls only engine speed , has nothing to do with spark
>timing - which is static , there is no advance mechanism . Study up John
>, it appears you don't actually know how either system works .
>

I didn't mention spark advance at all - just where the spark comes
from and the carb governor.
John T.

On 4/28/2024 11:32 AM, hubops@ccanoemail.com wrote:
> On Sun, 28 Apr 2024 07:06:47 -0500, Snag <snag_one@msn.com> wrote:
>
>> On 4/27/2024 7:17 PM, hubops@ccanoemail.com wrote:
>>> On Sat, 27 Apr 2024 17:23:25 -0600, Nick Cine <nickcine@is.invalid>
>>> wrote:
>>>
>>>> Took apart the pull mechanism of my single-cylinder Craftsman push lawn
>>>> mower today since it hasn't been used in a year and it wouldn't start in
>>>> one pull and the recoil spring mechanism was not recoiling after the first
>>>> pull (the cord just hung limp).
>>>>
>>>> https://i.postimg.cc/xjzzBZkW/lawnmower.jpg
>>>>
>>>> When I cleaned up the recoil mechanism & put it back together, I found some
>>>> of last year's gasoline, and it worked just fine (so anyone who says you
>>>> can't use old gas is gonna have to explain why it worked just fine for me
>>>> today).
>>>>
>>>> After two or three pulls with the choke locked open (otherwise it slides
>>>> shut too quickly), the motor started and after about ten seconds on choke,
>>>> I removed the clamp I put on the choke lever to keep it in place.
>>>>
>>>> I cleaned out the air filter too and cleaned up old grass in the blade area
>>>> (and a bunch of rope tangled around the driveshaft - I guess slowing down
>>>> the blade is what makes the motor shut off since I defeated the shutoff
>>>> mechanism due to it being a PITA as you always have to hold it on).
>>>>
>>>> Anyway, my question is I started to wonder how the spark is generated,
>>>> and I wondered how a simple (Craftsman) lawn mower advances its timing.
>>>>
>>>
>>>
>>> youtube can sometimes be your friend.
>>>
>>> https://www.youtube.com/watch?v=ckyFlX4CUVU
>>>
>>> Old gas isn't _always_ problematic ; very old gas _is_.
>>> In general, spark comes from the coil, activated by the
>>> magnet on the flywheel.
>>
>> It's called a "magneto"
>>
>>
>>> In general, the "governor" is ruled by the fins on the
>>> flywheel - working against a small spring on the flapper
>>> that controls the carb ..
>>> John T.
>>>
>>
>> The governor controls only engine speed , has nothing to do with spark
>> timing - which is static , there is no advance mechanism . Study up John
>> , it appears you don't actually know how either system works .
>>
>
> I didn't mention spark advance at all - just where the spark comes
> from and the carb governor.
> John T.
>

You oversimplified to the point that there's no meat on that sandwich
.. Usually a mark of those who do not understand the systems they are
talking about .
--
Snag
"They may take our lives but
they'll never take our freedom."
William Wallace

>>
>> I didn't mention spark advance at all - just where the spark comes
>> from and the carb governor.
>> John T.
>>
>
> You oversimplified to the point that there's no meat on that sandwich
>. Usually a mark of those who do not understand the systems they are
>talking about .
>

... and you changed magnet & coil to magneto. Thanks Einstein.
John T.