A bit blurry due to what I hope is a minor eye injury. Looks like a small black crater on the surface of the orb. Nasty things sneak past the safety specs.
The postman delivered the new heart for the chainsaw after dark on Sunday evening, very diligently.
The pdf service manual that a chap on the arboristsite forum had sent me back when I bought the saw came in very handy. I got panicked at one point looking at their pictures thinking I was going to have to take out the four retaining bolts that run up through the cylinder in order to get the ring compression widget back out, but in the end it was ok. Just a little like a Chinese wire puzzle, pushing the piston up into the cylinder and wiggling one end of the c shaped widget out around the bars of its cage until it could be snapped out to freedom. Only a bit of plastic, but worth keeping as the job of holding those rings in would be a bugger without it.
Once the saw had been taken off of anaesthetic and fuelled up it came to life after a very few tugs on its cord and seems to be working well again producing a positive shower of saw shavings.