Small Engines (Lawn Mowers, etc.): lawn mower reving down, briggs stratton engine, briggs stratton

Question
QUESTION: Hi,

I have a Bolens by MTD mower, 4.5HP Briggs & Stratton engine.  If I go forward, everything is OK.  But when I stop or pull back on it, it will almost stall.  You can actually see/hear it at http://mysite.verizon.net/vzet7zqu/lawnmower/

ANSWER: Hard to tell from the video, is the mower self-propelled?

How old is the mower?  Send me the model number on located on the sticker on the mower so I can look up the shut-off cable.  By the sound of the engine I do not believe it is a carburetor issue.  Does the mower start easy?

I would guess the shut-off cable may be stretched and when the handle moves the cable is grounding the ignition.  Look on the calbe itself and you will see the part number in white letters.

Eric

---------- FOLLOW-UP ----------

QUESTION: The mower is not self-propelled, and it is about 4.5 years old.  The mower does start easily.  Model no. is 11A-084E765 (also has 90012 underneath the first no.).  The no. on the shut off cable appears to be 746-0957 3120.

The reving down as I described it doesn't happen until it is warmed up.  Is the shut off cable hooked to the lever that I have to hold back to run the mower?  I have to release it about 3 inches from the handle before it begins to shut the engine off.

Answer
Is the fuel tank full when the problem occurs?  Have you replaced the spark plug?

The cable part number is 746-0957.  However, MTD cables are not prone to stretching.  Based on the model number the mower is only about three years old.  Have you ever cleaned the air filter?

Try a new spark plug before buying a new cable.
Eric