I have a Scotts lawnmower with a Briggs & Stratton 6HP engine. I
bought it several yrs. ago. I drain the gas tank every fall and change
the oil before every season. Also, I install a new spark plug every
other year (this year included).

Usually it's hard starting on the first mowing every year; after that,
however, it starts damn near every time on the first pull.

Now -- beginning halfway through this summer -- it has taken on the
habit of not wanting to start when the engine is hot. It still starts
on the first pull when it's cold. But every time I stop to empty the
grasscatcher, I can't restart. I have to wait 15 or more minutes
until the engine cools. Molto aggravating! Takes way longer to mow
the lawn, now.

Question: What in the world makes the engine *not* want to start after
it's been running awhile?

--My Aching Back