The3rd Earl Of Derby wrote:
Carpii wrote:
Hi., I just bought a brand new petrol mower this weekend. I measured
and filled the oil and petrol correctly. Its a 4 stroke engine

It starts without too much difficulty (though not as easy as Id
expected).
After mowing for maybe 30 seconds, the motor rapidly fades and then
stops.


At this point the starting cord is very tough to pull, and I
generally have to leave it for a while before I can start it as
easily as before.


Thats true as their will be pressure still in the piston chamber and
leaving it a while,the pressure is gradually diminishing.


There will only be pressure in the cylinder if it stops at, or approaching,
tdc on the compression stroke. Which it wouldn't. Ever. It should not be any
harder to start whether it's been running or not, in fact it will start
easier if it's warm for obvious reasons.

It's either partially seizing due to lack of oil, which seems unlikely as it
would probably keep running until it did seize properly, or the dead man's
handle is binding somehow when it's warm.

OP: Take it back to the shop.

Si