LawnBoy mower: speed oscillates; governor problem?
ge
which has gradually worsened, where the engine constantly changes
speed. It slows to near the point of stalling, and then cycles back
to 'normal' speed. It does this whether it's loaded or not.
It is not out of gas, and the gas flow seems unobstructed. The needle
valve works correctly when I blow on the fuel inlet. The spark plug
looks clean.
It has an (air-blown) vane-type governor, which moves when the speed
varies, as you might expect. Holding the governor in one position
seems to keep the speed constant. This makes me think that the
governor is the cause of the problem, but I'm having trouble picturing
how this could happen. It seems to move freely.
Any thoughts would be appreciated.
Thanks,
George
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Rileyesi
>which has gradually worsened, where the engine constantly changes
>speed. It slows to near the point of stalling, and then cycles back
>to 'normal' speed. It does this whether it's loaded or not.
>
>It is not out of gas, and the gas flow seems unobstructed. The needle
>valve works correctly when I blow on the fuel inlet. The spark plug
>looks clean.
>
>It has an (air-blown) vane-type governor, which moves when the speed
>varies, as you might expect. Holding the governor in one position
>seems to keep the speed constant. This makes me think that the
>governor is the cause of the problem, but I'm having trouble picturing
>how this could happen. It seems to move freely.
>
>Any thoughts would be appreciated.
>
>Thanks,
>George
How's the air filter look? Sometimes a blocked air intake filter can cause the
engine to 'breathe'.
ge
I forgot to say, it acted the same when I ran with the filter removed.
An odd thing about the governor: when the speed drops, the governor
should move to open the throttle; I think it didn't do that - when I
'corrected' it manually, I had to move it in the other direction.
mandacat
>On 15 May 2003 02:45:58 GMT, rile...@aol.com.gov (Rileyesi) wrote:
>
>>>We have a 2-cycle LawnBoy mower ("Silver Series"). It has a problem,
>>>which has gradually worsened, where the engine constantly changes
>>>speed. It slows to near the point of stalling, and then cycles back
>>>to 'normal' speed. It does this whether it's loaded or not.
>>>
>>>It is not out of gas, and the gas flow seems unobstructed. The needle
>>>valve works correctly when I blow on the fuel inlet. The spark plug
>>>looks clean.
>>>
>>>It has an (air-blown) vane-type governor, which moves when the speed
>>>varies, as you might expect. Holding the governor in one position
>>>seems to keep the speed constant. This makes me think that the
>>>governor is the cause of the problem, but I'm having trouble picturing
>>>how this could happen. It seems to move freely.
>>>
>>>Any thoughts would be appreciated.
>>>
>>>Thanks,
>>>George
>>
>>How's the air filter look? Sometimes a blocked air intake filter can cause the
>>engine to 'breathe'.
>
>I forgot to say, it acted the same when I ran with the filter removed.
>
>An odd thing about the governor: when the speed drops, the governor
>should move to open the throttle; I think it didn't do that - when I
>'corrected' it manually, I had to move it in the other direction.
Spring damaged or missing ??
>
>George
>
>
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>http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
>-----== Over 80,000 Newsgroups - 16 Different Servers! =-----
--
There can't be a solution if you've "Tried Everything"
mand...@carolina.rr.com
Bob M.
the throttle lever, if there is one, pulls a spring which attempts to open
the carb's throttle plate.
the governor (air or mechanical) pulls the carb's throttle plate closed as
the speed increases.
as the engine speed drops due to load, the governor should let the carb's
throttle plate open more to compensate for the drop in speed. once the load
gets lighter, the governor will close the carb's throttle plate again to
keep it from going too fast.
Most 2-cycle engines like to run at a speed around 3000 RPM. I've worked on
LawnBoy and Toro equipment that had no manual throttle setting - the
governor just ran the engine at whatever speed was set by the factory by
bending linkages or adjusting spring tension.
There may or may not be a governor return spring which would tend to pull
the throttle closed. My 5hp B&S engine is missing this spring and it lets
the throttle go to wide open when the engine is stopped. (A new spring is
waiting to be installed.)
With the engine stopped, move the air vane lever and learn which way it
moves to open and close the carb throttle plate. With the engine running,
you should be able to manually close the carb throttle plate and have the
spring pull it back open, and if you push it open, the governor should close
it back up.
Your engine may or may not have an idle speed screw on or near the carb
throttle mechanism. Depending on how it's set, the engine may idle and keep
running, or it may just shut off when set to the idle position. Again, if
you have no manual throttle control and the engine runs at only one speed,
there's no need for an idle setting at all.
An air vane governor also needs the engine shroud properly attached, as this
directs the air coming off the flywheel, to move the vane with varying
engine speeds. It probably won't work properly with any housing component
removed.
Bob M.
======
"ge" <ecc...@a-znet.com> wrote in message
news:3ec30132....@news.a-znet.com...
Dr. Doctor
pto seal starting to fail. that is where I would start if you checked all
other obvious possibilities.
Phisherman
LawnBoys. Make sure all your cables are properly installed and
working smoothly.
ge
take care of the problem. Plus, the top end speed is higher, which
seems an improvement.
Thanks to all,
Bob M.
for mechanical (non-air-vane) types. There's also a maximum speed for all
engines, and while you're getting more speed out of it now, you could have
exceeded its rated limit. Things tend to fly apart at high speeds, and a
piece of a blade slicing through your ankle wouldn't feel very nice.
If you have access to a small engine tachometer, or know a friend who has
one, or are friendly with a local repair shop, see if you can bring the
mower there and adjust the top speed to 3000 or maybe 3200 tops.
Bob M.
======
"ge" <ecc...@a-znet.com> wrote in message
news:3ec3a889....@news.a-znet.com...
Magnusfarce
carburetor. I had been letting the stored gasoline get stale, and this
caused problems with the carb. I rebuilt the carb (not as hard as it
sounds) and use fresh gas, and have had no more problems. Apparently newer
mowers are more susceptable to this sort of thing because of changes to carb
design required by emission standards.
- Magnusfarce
"Rileyesi" <rile...@aol.com.gov> wrote in message
news:20030514224558...@mb-m20.aol.com...
NMig
Model:10247. The speed of the mower oscillates while cutting the
grass. Any suggestions on how to rebuild the carb? Where to start?
Never done it before. Any pictures or instructions?
Thanks in advance.
"Magnusfarce" <magnu...@earthlink.net> wrote in message news:<xm7xa.343$rO.5...@newsread1.prod.itd.earthlink.net>...
A. Todesco
with grease, dirt and grass. Mine was so bad that it held only one
speed. When you cut into thicker grass, it would stall. I flushed it
with spray carb cleaner. Watch, as some of these will actually remove
the paint from the mower deck if it drips there.
TIA
news:9%wxa.360119$Si4.3...@rwcrnsc51.ops.asp.att.net:
> Any problem of this nature is best fixed by using a carburetor rebuild
> kit. Usually the diaphragm in the carb that has the accelerator pump
> ages and causes the problem. A kit is about $15 and it will take you
> about an hour.
> You'll go nuts trying to adjust things to cure a harware failure!
>
Small engine carburetors don't have accelerator pumps. Some with diaphragms
have automatic chokes. And all with diaphragms have fuel pumps. But none
have accelerator pumps.
Further, LawnBoy 2 cycle engines don't even have diaphragms. They have
reall float carburetors. Older ones have plastic carbs and cork floats.
Newer ones have Walbro aluminum carbs with plastic floats. But LawnBoys
have never had diaphragm carbs on their lawn mowers.
And those Briggs & Stratton carbs that have diaphragms don't have "kits".
The parts are sold separately.
Matt
Stormin Mormon
> It's hunting. I tried everything including
replacing entire carb.BEFORE GOING FURTHER PULL
SPARK PLUG AND VERIFY NOT FOULED! SHOULD BE
FAIRLY CLEAN! Mine did exact same thing when
I checked plug I couldn't believe I over looked
it. It runs like striped a@$ zebra now! By the
way don't bother auto CLOWNS or advanced idiots
as they have no clue. Go straight to Home Depot.
The plug needed was in stock and 4.30 less .
>
When I took a small engine repair course, the
teacher said the usual reason for hunting is
the governor spring gets a bit rusty, and
stiffens up.
--
.
Christopher A. Young
learn more about Jesus
. www.lds.org
.
.