10-08-2019, 12:08 PM
This is, as best as I can remember, a repeat of the post I put on here yesterday evening that apparently disappeared: The kick occurs when a cylinder fires. My timing is set so that when I turn the engine over slowly there is a small kick each time a plug fires - I think the kick is slight because the compression remains low as the rings and valve guides are worn. If the handle is pulled quickly through half a turn, this generates enough compression and it fires. Once, when setting the timing and getting it too advanced, on starting the engine it gave a severe kick that pulled the handle out of my hand - so that is to be avoided. As you know, the other force felt when turning the handle is the compression - on a tight unworn engine this is significant and makes it hard to rotate the engine smoothly by hand - on such an engine it would presumably be more risky to set the timing very close to the limit? Despite the lack of obvious compression, once running, the Ruby engine provides sufficient power for normal use.
Colin
Colin