Briggs-Stratton Quattro

Seven-yr-old MTD 22" rear-bagger. 4 hp Briggs-Stratton Quattro,
well maintained, doesn't smoke, oil level fine, carb is
clean in/out, air filter has been cleaned.

Motor starts fine, than it revs up, then nearly dies,
then revs up, then nearly dies, etc etc. It -does-
carbonize spark plug electrodes ("black plug disease"),
and I thought that was the problem, but when I put a
fresh plug in, it ran the same as with the black plug.

Anybody got any idea what might be going on?

TIA,
Puddin'

************************************************** ****
*** Puddin' Man PuddingDotMan at GmailDotCom ***
************************************************** ****;

Likely a sticking float , clogged jet or airleak . probably time for a
carb cleaning.

All carbs have a fuel bowl and float system or you would have a direct
flow of gas into the motor filling the engine completely with gas till
it would run out the carb and exuast, even filling the crankcase to all
gas. The fuel bowl is not in the tank.

This often happens when the speed regulator (governer) doesn't work
right. These engines have air vanes, and often times a squirrel or some
other critter has made a home inside, and the nest blocks the vane.

Take off the top cap (around the spinning part on the top, where the
pull cord goes in) and I bet you find it. I used to do this every
spring to mine.

ive seen many of these with the small passage in the fuel bowl nut
clogged. you can take the nut off and use a needle or a tag wire to run
thru it and then blow it out. this is also a good time to take the fuel
bowl off and was it out. if you still have a problem after this. i
would snug up the head bolts, check the flywheel key to see if its
partially sheared. there is a oring that goes on between the engine and
the carb that may be worn,, or the tube that the oring goes on may be
worn ,and a gasket on the other end of that tube that may have blew.its
easy to check the intake tube while your checking flywheel key. .....
another common problem is the valve clearance closes up so the valves
dont shut as well. you can use a file between the lifter and valve stem
to get the clearance back where it should be..006 intake,,,.011 ex.at
top dead center.. lucas.

On Wed, 20 Apr 2005 14:20:56 -0400, wrote:

ive seen many of these with the small passage in the fuel bowl nut
clogged. you can take the nut off and use a needle or a tag wire to run
thru it and then blow it out.

To repeat, it is a B&S Quattro, 4 hp.

I could find no fuel bowl nut.

this is also a good time to take the fuel
bowl off and was it out.

Fuel bowl is part of the gas tank. Can't take it off.
But I cleaned it out. Wasn't very dirty, minimal residue only.

if you still have a problem after this. i
would snug up the head bolts, check the flywheel key to see if its
partially sheared. there is a oring that goes on between the engine and
the carb that may be worn,, or the tube that the oring goes on may be
worn ,and a gasket on the other end of that tube that may have blew.its
easy to check the intake tube while your checking flywheel key. .....
another common problem is the valve clearance closes up so the valves
dont shut as well. you can use a file between the lifter and valve stem
to get the clearance back where it should be..006 intake,,,.011 ex.at
top dead center.. lucas.

Head bolts were tight.

It fouls spark plugs. Gotta be a fuel/air mixture problem.
Carb/tank is all clean, no apparent problem. Compression
feels a little weak.

Still don't know what the problem is ...

Why do I see so many B&S mowers sitting in the alley
waiting for the trashman? They are made to be lo-price.
To my knowledge, "They Ain't Much Designed To Be Worked
On".

Thanks,
Puddin'


************************************************** ****
*** Puddin' Man PuddingDotMan at GmailDotCom ***
************************************************** ****;

hi, if you have the type carb that has a flat gasket between it and the
tank,, that rubber gasket can cause it not to run if it gets streched..
lucas

On Wed, 20 Apr 2005 14:03:03 GMT, (Puddin' Man)
wrote:

Briggs-Stratton Quattro

Seven-yr-old MTD 22" rear-bagger. 4 hp Briggs-Stratton Quattro,
well maintained, doesn't smoke, oil level fine, carb is
clean in/out, air filter has been cleaned.

Motor starts fine, than it revs up, then nearly dies,
then revs up, then nearly dies, etc etc. It -does-
carbonize spark plug electrodes ("black plug disease"),
and I thought that was the problem, but when I put a
fresh plug in, it ran the same as with the black plug.

Anybody got any idea what might be going on?

TIA,
Puddin'

************************************************* *****
*** Puddin' Man PuddingDotMan at GmailDotCom ***
************************************************* *****;
Last week had the same problem with my 10 year old murray with B&S 5hp
Quattro. (Lets remember that these engines have a 250 hour life
expectancy from B&S)
Mine ran/runs great and hated to throw it away just because I left
some gas in the carb over the winter. Self propelled costs around $300
to replace.... now it looks like I'll get at least another season out
of it..

You'll need to google +"Briggs & Stratton"+Quattro
or go here and look for Engine IPL (illustrated parts list) to see
the breakdown
http://www.briggsandstratton.com/dis...sp?DocID=64103

You'll need the model of engine (not mower) it will be on shroud that
covers flywheel stamped in the end just above the spark plug. You'll
have to remove some "stuff" depending upon your model to get to this
number.

Once you find the B&S web site, search for that model number. You'll
end up with probably a .pdf file showing breakdown of engine.

Note that there is probably more than one model carb for your engine ,
you'll have to figure which one. Usually asks, do you have choke or
primer bulb.

On mine (which may vary quite a bit from yours) I had a bolt in
bottom of carburetor bowl which acts as a jet. Using carb cleaner and
very fine wire (I used safety wire) clean the gunk. Clean the gunk
from needle and seat under (above) the float.
My "carb to intake" seal is a "O" ring.... Looked fine.
I had to take carb off, put back on 3 times till I decided to put a
little gasket sealer on flange near "O" ring to help seal. On these
engines a little vacuum leak will cause it to not suck gas.. Till I
found this air leak, mine would run great as long as I kept pressing
primer bulb.

I spent $8 to fix mine including oil change and pull rope change..
If it wouldn't have worked after that,, I'd have dumped it.. It being
10 years old....
Chuck

"Chuck" wrote in message
...

(Lets remember that these engines have a 250 hour life
expectancy from B&S)

Is this 250 hour life true of the older B & S engines? If so I have several
living in the twilight zone. But then I guess that figure must be an
average.


Colbyt

On Mon, 25 Apr 2005 15:44:09 -0400, "Colbyt"
wrote:


"Chuck" wrote in message
.. .

(Lets remember that these engines have a 250 hour life
expectancy from B&S)

Is this 250 hour life true of the older B & S engines? If so I have several
living in the twilight zone. But then I guess that figure must be an
average.


Colbyt

I saw the 250 hour figure on the b&s web site,, but now older ones are
probably different..
Modern ones ya can't even adjust mixture (but no need to if it's
already right.) No idle speed screw....
Chuck

You ****ing idiots: The "250 hour" rating is how long the engine is
warranted to comply with EPA requirements. It has nothing to do with how
long the engine is supposed to last.

Take your heads out of your asses and read once in a while.



"Chuck" wrote in message
...
On Mon, 25 Apr 2005 15:44:09 -0400, "Colbyt"
wrote:


"Chuck" wrote in message
. ..

(Lets remember that these engines have a 250 hour life
expectancy from B&S)

Is this 250 hour life true of the older B & S engines? If so I have
several
living in the twilight zone. But then I guess that figure must be an
average.


Colbyt

I saw the 250 hour figure on the b&s web site,, but now older ones are
probably different..
Modern ones ya can't even adjust mixture (but no need to if it's
already right.) No idle speed screw....
Chuck

250 hr is till it will pollute due to worn rings you may get 100-250
more hours than that you may not. There are higher hour rated motors by
B&S 500-1000 for example but it a true indicator of a motors
construction and durability .Using the EPA rating is a good way for you
to compare a motors life expectency. B&S and others even honda have a
light duty and commercial service line. Honda used to be only Commercial
duty but now has the cheap line to.

On Tue, 26 Apr 2005 18:43:45 GMT, "Oscar_Lives"
wrote:

You ****ing idiots: The "250 hour" rating is how long the engine is
warranted to comply with EPA requirements. It has nothing to do with how
long the engine is supposed to last.

Take your heads out of your asses and read once in a while.



"Chuck" wrote in message
.. .
On Mon, 25 Apr 2005 15:44:09 -0400, "Colbyt"
wrote:


"Chuck" wrote in message
...

(Lets remember that these engines have a 250 hour life
expectancy from B&S)

Is this 250 hour life true of the older B & S engines? If so I have
several
living in the twilight zone. But then I guess that figure must be an
average.


Colbyt

I saw the 250 hour figure on the b&s web site,, but now older ones are
probably different..
Modern ones ya can't even adjust mixture (but no need to if it's
already right.) No idle speed screw....
Chuck

Go find a "Hot" water heater to troll about..