Chris Bacon 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

That sounds like a blockage in the fuel system somewhere...

Too true, sounds like it is seizing. If you are using two stroke in a
four stroke engine, it will choke up until the oil drains out. It will
eventually soot up the plug.

There is a minor chance of it clonking due to a weak mixture as the
unburned oil counts as petrol starvation. It's only an interesting
accademic point for model airplane engines though.
:
What mix of oil and petrol are you using, Carpii?

The tank valve is probably blocked. You will find it runs for a little
longer on a near empty tank than on a full one if that is so but just
clean the vent rather than miss around with it. Also, check the air
filter is clean.

As long as there is some oil in the crank case there is no problem with
the oil situation. If you take the plug out its colour will tell you if
the mixture is too oily, too rich or whatever. If it's not that then it
might be te timing. This will "go out" if you mow a brick or something.

I wouldn't mess around with anything technical, just take it back if
it's not the vent or air filter.