Thanks for that Mark. I've had a close look at a couple of sets of very worn chonda rings in the past (courtesy of Rob) and I believe they were of good quality and had lasted a very long time in service. They seem visually identical (except for markings) to late-model original Honda rings. If you only have an 0.008" gap in the second ring (the fastest wearing one, and the only un-chromed one), I don't think that engine has been used beyond a bare running-in period at most. That is close to the minimum gap specification for a factory-new engine.

A few months ago we had a member (charmaine) reporting symptoms which sounded very like the results of a solidly stuck-closed PCV valve on a chonda, and I couldn't understand how it could happen with the Honda disk valve. Now I think I can see what happened - that cheap flapper looks as if it were specially designed to stick, and the vent-hole below it looks to be a fraction the size of the Honda one, so it may block as well, especially if the so-called valve is stuck closed some of the time.

[Linked Image]

(Picture cropped from one of yours, above, with red circle added around PCV port).
Like the plastic camshaft and simplified decompressor from the GXV140 that we are seeing on your GXV120 clones, it seems at least some chondas are not true copies of Hondas. So far it seems the Pope and Scott Bonnar chondas are on my don't bother list. I've seen some of the details of a number of Sanli GXV120 chondas, which seemed to be quite accurate Honda copies - but I don't recall seeing the camshaft.

To be fair to the GXV140's plastic camshaft and clockwork-style decompressor, they seem to work properly on the GXV140s as far as I know. However the GXV140 was a sort of interim, ultra-lightweight engine made in the US-only, and it went out of production in 2003. The GXV120 is still in production now, after 31 years so far.

Last edited by grumpy; 04/10/14 10:44 PM. Reason: Add detail