In another thread (Shop built roller starter) chainsaw decompressors were mentioned and as my engine has spare plug holes I thought I would try them, the cheapest I found were £4.09 each so I ordered a pair, the thread is M10 x 1mm and the old plugs I have are just under 9mm bore when the insulator was removed.
So I cut a pair down, drilled 9mm and tapped I soon had a them ready. Dragged the bike out and started it just to make sure it was running (not used her for a month) popped the decompressors in and gave her a swift kick, started no problem with much less effort (I normally don't use the valve lifters being overweight and it starts first kick), repeated several times and started every time.
So I shall be keeping them in, eventually, but I need to make new adaptors as cutting plugs down removes the hexagon to tighten them in properly.
I shall make some from hex brass bar and not take the 10mm hole all the way through but the last bit at the cylinder end I will drill smaller than the decompressor valve head, this is in case it ever fails nothing can drop into the cylinder.
A very useful little mod and one would be a benefit on a couple of different engines I have.
Chris
So I cut a pair down, drilled 9mm and tapped I soon had a them ready. Dragged the bike out and started it just to make sure it was running (not used her for a month) popped the decompressors in and gave her a swift kick, started no problem with much less effort (I normally don't use the valve lifters being overweight and it starts first kick), repeated several times and started every time.
So I shall be keeping them in, eventually, but I need to make new adaptors as cutting plugs down removes the hexagon to tighten them in properly.
I shall make some from hex brass bar and not take the 10mm hole all the way through but the last bit at the cylinder end I will drill smaller than the decompressor valve head, this is in case it ever fails nothing can drop into the cylinder.
A very useful little mod and one would be a benefit on a couple of different engines I have.
Chris