Thanks for the experience re decompressors Blumbly.
So I pulled it down again and removed the decompressor and found it open, and easy to close with a suck on the manifold tube.
Then thought it might be a timing problem, as I replaced the points a couple of days ago. So I set about removing the flywheel and found it very difficult, which is surprising as I had it off just a day ago. Eventually I got it off and examined it carefully for any burrs or damage to the key, shaft, flywheel hole, but found it in good condition, just a perfect fit. So I lightly greased the taper and put it back together, having found the points in position. There is no adjustable timing I can see as the points can only be adjusted for gap. Tightened it up and it started OK, idled OK. No kick back on the starter cord.
Cut grass very cleanly with the new blades. Can actually hear the blades slice through the grass.
So I'm none the wiser. Seems the engine is a bit temperamental. previously it has been reliable and consistent
Styx
