Huh?Huh?O.K., I never said I've seen it all, but this is definately a new one. I'm doing a CA77 motor for fellow member Jerrybb. I pull the top end, see .75 stamped on the piston, which was in good shape btw, and order a new set of .75 rings. The cyl liners were toast, so I get a used std bore cyl off of Ebay. It shows up today, and the .75 pistons drop right in. Really, I guess it's not std after all. So I measure the bore, and it's std. Then I clean the tops of the pistons, and what the HUH! Here's a pic. Anyone ever seen anything like this before? Someone turn them down? Mismarked from the factory? I'm at a loss!
Re: Huh?Those are not CA77 pistons. ..........lm
HUH?Whomever was in that engine before apparently put it back together with an exotic flare. I told Jerry before that it seemed to me that the person either had no clue what they were doing or knew EXACTLY what they were doing. I suggest the latter is the case.
One explanation would be that whomever that was took some .75 oversize pistons and turned them down to standard size. I would never believe these pistons came from Honda (or any other piston maker) as pictured. Do standard rings fit okay in the grooves? It would seem like they would have had to turn the grooves a bit as well. A lot of work no doubt, but if it meant turning old boat anchor pistons into something usable and they had more time than money, perhaps it made sense. Or, maybe they just wanted to see if they could do it for the challenge. Seeing that they took the time to stamp the piston to reflect STD bore is another indication that they knew exactly what they were doing. He probably even thought to himself, "I wonder what the guy who takes this apart will think?" Davo - I've got a set of -275 std rings that may??? fit those. They have about 1000 miles on them and are still well within spec if you want to give them a try.
-48 swmrescue@cox.net
Well, at least my Dream is giving a lot of fodder for discussions on the forum. I know Davo will get it right but I think it generates more questions than answers. How dull to have a normal bike! One more thing, I'm hoping conbs is right(above) but I'm not so sure. The wiring is pretty sloppy at the coils and primarys so I'm wondering just how well other things were done. On the other hand, it did run pretty well even though one side had really low compression with broken rings. We'll see...
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