[infiniteMPG]

I have a handed down Yardman Lawn Tractor with a 19.5HP Briggs &
Stratton 3672CN engine. Got this last year and ran fine all year
without problems starting or running. Haven't run it in several
months and when I tried it last week the battery was too low to turn
engine over. Replaced battery but then engine would just crank and
crank and never fire. Pulled air cleaner off and sprayed some starter
fluid in and would run until fluid ran out and then cut off. Pulled
carb and cleaned everything I could with carb cleaner and made sure
everything was free moving. Pulled cap lock screws out and float was
trapped under mid-gasket and didn't have a new gasket so I sprayed in
the float area with carb cleaner without removing it. Pulled the plug
on the side of the float area and let the carb cleaner run completely
thru. Replaced fuel filter even though fuel was free flowing.
Replaced carb and after starting with starter fluid a few time, it
started running on it's own. Idled fast and stayed running smooth as
long as I just let it sit there.

I put it in gear and moved forward and backwards a few times and as
soon as any additional load was put on the engine, the engine would
slow, the lower butterfly below the carb would start to shut and the
engine would just cut off. Also, if I even just barely started to
engage the blades the engine would die. Was told there was also an
oil level safety on this engine but the oil level is correct. It
appears that the engine runs fine but has no power under load. When
any load is added to the idle condition the engine dies. I tried
adjusting the metering needle screw on the carb but that had no effect
unless I went in too far and then the engine would sputter and die.

Any and all help would be greatly appreciated as with the recent rains
I will soon need a field guide to find my front door :O)

Scott

[infiniteMPG]

Still got carb problems.

The carb is pretty simple, the only thing I didn't dig into was the
float. When the top cap is removed the gasket is stuck to the bottom
of the carb housing. The float mechanism seems mounted to something
in the top half and something is under the gasket in the bottom half.
So unless I scrap the gasket off and replace it I can't seperate the
halves. Does this sound like float issues? Should the entire float
mechanism be relaced or could it just be sticking?

Sounds like a trip to the parts shop to get a gasket and a float or a
complete rebuild kit. I checked and did not see ANY numbers or
identifiers on the carb anywhere. How do you ask for a rebuild kit or
float or would there just be one carb available on the 19.5hp 3672CN
engine?

Thanks,
Scott

[infiniteMPG]

It could go by the make and serial number of the mower but you could
take the carb with you also.

They wanted the stamped number off the engine block. I had the model
of the mower but no help as it's old.

Sounds like the engine is dying because it's starving for fuel (unless it makes black smoke) when the governor pulls the throttle up and that could be a sign of low fuel level in the bowl (float/needle valve problem) You probably should call the parts department and ask the exactly what they need to look up a parts list for that carb.

I would of checked the float out better but didn't have the
replacement gasket and the float is attached to the top part of the
carb housing and some of it extends below the gasket so I couldn't
remove it without scraping off the gasket. The local shop (and I
trust these guys) is open tomorrow 8-1 so I am running by there. Good
idea to bring the carb. Two bolts and it's in my hand. My Dad (who I
got the mower from) just told me that he thinks it's carbon buildup in
the heads and/or the exhaust system. I kind of doubt that as that
would cause it to run bad all the time and not just when going under
load. My hunch is pointing me towards the float as even when it
starts to die if I spray starter fluid (or dribble some gas) directly
in the carb it stays running until the fuel is used up. The float is
not in a seperate "bowl" with a releif spring screw plug in the bottom
like many small engines, it's in a machined out section of the bottom
housing and only has one hex plug in the side and no drain in the
bottom.

Thanks for the advice, I need it :O)
Scott

[Oren]

On Fri, 15 Jun 2007 14:00:08 -0400, Meat Plow
wrote:

On Fri, 15 Jun 2007 14:18:31 +0000, infiniteMPG wrote:

Still got carb problems.

The carb is pretty simple, the only thing I didn't dig into was the
float. When the top cap is removed the gasket is stuck to the bottom
of the carb housing. The float mechanism seems mounted to something
in the top half and something is under the gasket in the bottom half.
So unless I scrap the gasket off and replace it I can't seperate the
halves. Does this sound like float issues? Should the entire float
mechanism be relaced or could it just be sticking?

If the gasket is seriously stuck - it needs to be replaced! You can
make one with gasket material from the auto store. There may be a
vacuum leak at the gasket.

The float neddle can be worn on the tip (rubber point) and needs to be
checked to ensure the float works, Use a gauge to set the float...


Sounds like a trip to the parts shop to get a gasket and a float or a
complete rebuild kit. I checked and did not see ANY numbers or
identifiers on the carb anywhere. How do you ask for a rebuild kit or
float or would there just be one carb available on the 19.5hp 3672CN
engine?

Go to the B&S site, locate your model..they may sell the kit. Check
for a local B&S service center.


Thanks,
Scott

It could go by the make and serial number of the mower but you could
take the carb with you also. Sounds like the engine is dying because it's
starving for fuel (unless it makes black smoke) when the governor pulls
the throttle up and that could be a sign of low fuel level in the bowl
(float/needle valve problem) You probably should call the parts department
and ask the exactly what they need to look up a parts list for that carb.


Sticky/worn float needle is a great place to look. So far the OP has
not gotten into the float parts, unless I missed it :-(
-
--
Oren

"The voices in my head may not be real, but they have some good ideas!"

[Oren]

On Fri, 15 Jun 2007 20:41:34 -0000, infiniteMPG
wrote:

I would of checked the float out better but didn't have the
replacement gasket and the float is attached to the top part of the
carb housing and some of it extends below the gasket so I couldn't
remove it without scraping off the gasket. The local shop (and I
trust these guys) is open tomorrow 8-1 so I am running by there. Good
idea to bring the carb. Two bolts and it's in my hand. My Dad (who I
got the mower from) just told me that he thinks it's carbon buildup in
the heads and/or the exhaust system. I kind of doubt that as that
would cause it to run bad all the time and not just when going under
load. My hunch is pointing me towards the float as even when it
starts to die if I spray starter fluid (or dribble some gas) directly
in the carb it stays running until the fuel is used up. The float is
not in a seperate "bowl" with a releif spring screw plug in the bottom
like many small engines, it's in a machined out section of the bottom
housing and only has one hex plug in the side and no drain in the
bottom.

Thanks for the advice, I need it :O)
Scott

I agree it is not a carbon build-up on the head or piston. Pull the
plug a look at the piston at top dead center, if you think it's
necessary.

The spray makes it run, because it is starving for fuel as mentioned
earlier.

The float and it's operation; would be my focus, for the moment.

--
Oren

"The voices in my head may not be real, but they have some good ideas!"

[infiniteMPG]

Update 6/16.2007 - Pulled a little 'stunt' last evening trying to get
the model off the engine. Was told several places to look and ended
up pulling all the side panels and hood off the mower and the side
covers. When I was about to pull the top cover off I happened to look
and there is a tag on the top of the top cover right in my face.
Sometimes the most obvious is the hardest to notice.... duh!

MODEL - 42E777 / TYPE - 1280 01 / CODE - 9509215A

Ran down to a local mower shop this morning and got a complete carb
rebuild kit for $13. Alos grabbed a new air filter and foam filter
cover. Didn't know what I was doing totally and no instructions so I
set off to do my best.

Pulled everything apart, got the float out, cleaned all the ports,
replaced all the parts I could (one jet housing I couldn't get out and
didn't want to damage so I cleaned as good as I could). Replaced the
float, the springs, gaskets, seals, everything I could. Put
everything back together, mounted it up and hoped for the best.

Sprayed a little starter fluid in and fired her up. Started right up,
settled to idle quick and then I tried engaging the blades to put a
load on the engine and it purred great! Put the filter on, restarted
it and mowed. Nice feeling.

Was running a little s-l-o-w at full throttle so I think I have to
adjust the settings a little but managed to mow a good portion of the
yard before the sun baked my brain. Appears there are a couple
adjustments on the carb, a needle screw under the bowl section of the
float (which I beleive adjusts the mix), a screw on the throttle lever
which I think only adjusts the idle speed, and a screw on the front of
the engine that looks to be part of the throttle cable setting. Any
help to increase the full throttle speed (I may of turned something
when trying to fix it before)?

Thanks again for your assistance,
Scott

[Oren]

On Sat, 16 Jun 2007 10:41:15 -0700, infiniteMPG
wrote:

Update 6/16.2007 - Pulled a little 'stunt' last evening trying to get
the model off the engine. Was told several places to look and ended
up pulling all the side panels and hood off the mower and the side
covers. When I was about to pull the top cover off I happened to look
and there is a tag on the top of the top cover right in my face.
Sometimes the most obvious is the hardest to notice.... duh!

MODEL - 42E777 / TYPE - 1280 01 / CODE - 9509215A

Ran down to a local mower shop this morning and got a complete carb
rebuild kit for $13. Alos grabbed a new air filter and foam filter
cover. Didn't know what I was doing totally and no instructions so I
set off to do my best.

Odd, there were no instructions. My last kit had the instructions and
the float gauge....


Pulled everything apart, got the float out, cleaned all the ports,
replaced all the parts I could (one jet housing I couldn't get out and
didn't want to damage so I cleaned as good as I could). Replaced the
float, the springs, gaskets, seals, everything I could. Put
everything back together, mounted it up and hoped for the best.

Sprayed a little starter fluid in and fired her up. Started right up,
settled to idle quick and then I tried engaging the blades to put a
load on the engine and it purred great! Put the filter on, restarted
it and mowed. Nice feeling.

It does feel good; especially when extra parts are left in the kit
box! :-)


Was running a little s-l-o-w at full throttle so I think I have to
adjust the settings a little but managed to mow a good portion of the
yard before the sun baked my brain. Appears there are a couple
adjustments on the carb, a needle screw under the bowl section of the
float (which I beleive adjusts the mix), a screw on the throttle lever
which I think only adjusts the idle speed, and a screw on the front of
the engine that looks to be part of the throttle cable setting. Any
help to increase the full throttle speed (I may of turned something
when trying to fix it before)?

Just my method, but I increase the RPM on the engine and adjust it by
"ear" At a higher RPM I can "tune" it.

Make small turns 1/8 to 1/4 turns on the screw.




Thanks again for your assistance,
Scott
--
Oren

...through the use of electrical or duct tape, achieve the configuration in the photo..

[infiniteMPG]

Just my method, but I increase the RPM on the engine and adjust it by
"ear" At a higher RPM I can "tune" it. Make small turns 1/8 to 1/4
turns on the screw.

On which screw? There were three, one by the float (I think mix), one
on the side of the carb (I think just low idle speed), and one down on
the front of the engine that the throttle linkage runs thru. I guess
I would assume that one?

Yeah, feels good and looks good. Was waiting for a letter from the
neighborhood nazis.... errr, I mean the homeowner's association
folks :O) Oh yeah, didn't put this in as I didn't think it mattered
much at the time but when I was remounting the carb a couple days ago
I must of had something not seated right and when I cranked on the
front carb mount bolt I heard a loud POP and when I disassembled it I
found the front tab flange the carb mounts on broke off in the cast
metal. I actually used J-B Weld and it's solid and works. Love that
stuff! :O)

Thanks again,
Scott

[Oren]

On Sat, 16 Jun 2007 12:38:57 -0700, infiniteMPG
wrote:

Just my method, but I increase the RPM on the engine and adjust it by
"ear" At a higher RPM I can "tune" it. Make small turns 1/8 to 1/4
turns on the screw.

On which screw? There were three, one by the float (I think mix), one
on the side of the carb (I think just low idle speed), and one down on
the front of the engine that the throttle linkage runs thru. I guess
I would assume that one?

Mixture screw, then adjust the idle when she sounds good on the "ear
tune"!


Yeah, feels good and looks good. Was waiting for a letter from the
neighborhood nazis.... errr, I mean the homeowner's association
folks :O) Oh yeah, didn't put this in as I didn't think it mattered
much at the time but when I was remounting the carb a couple days ago
I must of had something not seated right and when I cranked on the
front carb mount bolt I heard a loud POP and when I disassembled it I
found the front tab flange the carb mounts on broke off in the cast
metal. I actually used J-B Weld and it's solid and works. Love that
stuff! :O)

That POP is telling you something. We just have to listen. Better the
flange than the bolt in the block.

I've never been able to adjust a carb with a broken bolt flange :-))


Thanks again,
Scott

--
Oren

...through the use of electrical or duct tape, achieve the configuration in the photo..

[infiniteMPG]

Didn't see any way to add a PDF file to the messages so I uploaded it
and this is the link :

http://www.infinitempg.com/carbimages.pdf

This shows the right and left side view of the carb on the front of
the engine, air cleaner assembly completely removed. I tweaked around
with the mixture screw yesterday (this is not shown in either picture,
it's below the square gas inlet assembly on the front of the carb) and
got it to smooth out. Then played with the idle adjustment screw (on
the right side view right beside the breather hose hanging loose). I
got it to idle fast and ride a lot better then before but not
perfect. Still managed to mow the rest of my yard. The thing I
noticed is that the throttle adjustment didn't do a thing for changing
the engine speed, the only thing I could do is adjust the idle screw.
The throttle cable is the cable you can see in the bottom of the left
side view and there is an adjustment screw where it mounts to the
front of the engine. This runs thru a linkage and ends up changing
the plate stop that rests against the idle adjustment screw in the
right side view. When I move the throttle adjustment it moves the
linkage on the front of the engine but it barely causes any movement
in the stop plate on the side of the carb. Not sure what's up with
that as I used to be able to throttle it so slow with the adjustment
before the engine would almost cut off.

So I still have some adjustment issues but now (hopefully) you can see
the setup I have on the engine.

I've never been able to adjust a carb with a broken bolt flange :-))

Me neither as I repaired the flange with JB Weld and it seems to be
holding solid and true :O) That "POP" is a sound I'd rather not
hear again :O)

Thanks,
Scott

[infiniteMPG]

Oh yeah, the place the throttle linkage connects into the system on
the front of the engine looks like this :

http://www.infinitempg.com/carbadj.jpg

Didn't know if that would help but it shows the way this linkage cable
ties in.

Thanks again,
Scott

[Oren]

On Tue, 19 Jun 2007 13:57:03 -0700, infiniteMPG
wrote:

Didn't see any way to add a PDF file to the messages so I uploaded it
and this is the link :

http://www.infinitempg.com/carbimages.pdf

This shows the right and left side view of the carb on the front of
the engine, air cleaner assembly completely removed. I tweaked around
with the mixture screw yesterday (this is not shown in either picture,
it's below the square gas inlet assembly on the front of the carb) and
got it to smooth out. Then played with the idle adjustment screw (on
the right side view right beside the breather hose hanging loose). I
got it to idle fast and ride a lot better then before but not
perfect. Still managed to mow the rest of my yard. The thing I
noticed is that the throttle adjustment didn't do a thing for changing
the engine speed, the only thing I could do is adjust the idle screw.
The throttle cable is the cable you can see in the bottom of the left
side view and there is an adjustment screw where it mounts to the
front of the engine. This runs thru a linkage and ends up changing
the plate stop that rests against the idle adjustment screw in the
right side view. When I move the throttle adjustment it moves the
linkage on the front of the engine but it barely causes any movement
in the stop plate on the side of the carb. Not sure what's up with
that as I used to be able to throttle it so slow with the adjustment
before the engine would almost cut off.

The throttle cable can be binding/or not adjusted.

From the end view of the throttle cable spray a lubricant inside the
cable and hold the end up so the lube runs inside the cable casing..
move the cable back and forth to ensure it operates smoothly. Then
attach it back to the carb and adjust the range of movement.

(Tortoise - Rabbit)




So I still have some adjustment issues but now (hopefully) you can see
the setup I have on the engine.

I've never been able to adjust a carb with a broken bolt flange :-))

Me neither as I repaired the flange with JB Weld and it seems to be
holding solid and true :O) That "POP" is a sound I'd rather not
hear again :O)

Thanks,
Scott
--
Oren

...through the use of electrical or duct tape, achieve the configuration in the photo..

[Oren]

On Tue, 19 Jun 2007 14:03:17 -0700, infiniteMPG
wrote:

Oh yeah, the place the throttle linkage connects into the system on
the front of the engine looks like this :

http://www.infinitempg.com/carbadj.jpg

Didn't know if that would help but it shows the way this linkage cable
ties in.

Thanks again,
Scott

Are there any kinks, bends, or loose connections along this cable?

Is it difficult to move; meaning corrosion in the casing? Lube as
mentioned to get the full range of motion.

--
Oren

...through the use of electrical or duct tape, achieve the configuration in the photo..