Ryobi Chainsaw PCP 4040 16" will not start after mistakenly
mixing chainsaw oil in petrol 50-1,ran for 10 minutes,then
seized up.freed it by adding a few drops of penetrating
oil into plug hole,than knocking the pull-cord fly wheel
round with a piece of wood,gently,a couple of times,
which freed the piston.Refilled with correct mixture,but
now will not start.Tried every thing.

Peter, July 2008

The piston and bore are scored due to lack of oil- therefore you have no compression to start the engine. The machine is scrap unless you want to buy a new piston and barrell at £100+

pleasant, August 2008