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