I'm glad you posted that, Mark - I see it has not only a plastic camshaft, but a very simple decompressor mechanism that may or may not stand up in the long term. That whole assembly is copied from the GXV140 instead of the GXV120 which the remainder of those engines is cloned from. I'm disappointed - the GXV120 is my favourite small mower engine, and I had been thinking I might one day acquire a chonda of 120 cc for my own use. That idea is now off the table, unless I fitted a GXV120 or GXV160 Honda camshaft (all cast iron, with a decompressor of considerable elegance as well as excellence).
You will need to look closely at the piston rings, to see if they are significantly rusty. The crankshaft is cast iron, and does not rust easily, and the aluminium connecting rod doesn't rust at all. Note in the bottom of your last picture you see the large oil return passage, which shows Briggs how it should be done.
Reed valves are used in some of the better 2 stroke engines, but I'm cautious of the idea of using them as PCV valves. However I want to see their design before I express any negative views.
Last edited by grumpy; 04/10/14 10:45 PM. Reason: Add detail
